Campaigns

A campaign sends a sequence of emails to a list of contacts, spread across your connected mailboxes. Warmbly handles timing, volume limits, and mailbox rotation so sending looks natural and stays safe.

Shared workspace access

Campaigns belong to the workspace. Members with View campaigns can read campaign details, steps and activity logs regardless of who created them. Manage campaigns allows members to edit settings, create or edit steps, arrange the step canvas and delete steps. Campaign overview metrics require View analytics. See Team and roles for permission details.

Select the workspace that owns the campaign before opening it. Creating a campaign does not grant access to it from a different workspace.

Create a campaign

Campaigns > New campaign opens a four-step flow. A campaign is a first email and, optionally, follow-ups that stop for anyone who replies.

1. Leads: name the campaign at the top (left blank, it is named after its first list, or "Campaign" and the date; rename it any time), then pick one or more lead lists. Lists are your segments, shown with how many leads each holds; someone on several lists is emailed once, and the total below counts each lead once. Import new leads takes you to Contacts to bring in a CSV and keeps the draft for when you return. Picking no list is fine: Continue without leads creates the campaign so you can add leads afterwards.
2. Emails: the same editor as the Steps tab, with templates, Write with AI, variables, a preview rendered through the send engine and the content score. Add follow-ups here, each sent a number of days after the previous email (and stopping for anyone who replies, when Stop on reply is on). Add the usual two follow-ups adds two at 3 and 7 days. A follow-up with no subject replies in the same thread. The emails can also be left for the Steps tab, where you can branch them and add A/B variants.
3. Schedule: start at launch or on a date, the timezone, sending days and hours, the mailbox tags to send from, and the daily limit per mailbox. Every mailbox in the pool is listed with what it can send: Ramping up while it is still graduating from warmup, Reduced volume in a watch or throttled health band, On hold, DNS failing or Resting when it will not send. Tracking, UTM parameters, the unsubscribe header and stop on reply are under Tracking and replies.
4. Review: the finish date and a day-by-day chart of first emails and follow-ups against what the pool can send, what is setting the pace, and a summary with a link back to each step.

While you work, a Launch plan beside the Leads and Schedule steps keeps the estimate current. See How the estimate works.

The flow ends in Save as draft or Launch (Schedule when it starts on a date). Launch creates the campaign, links its lists (so it keeps enrolling leads who join them later, exactly like linking a segment) and opens the campaign's launch dialog. That dialog runs the pre-send checks and the launch check on your list before anything sends, just like Start on a campaign page. Launch stays unavailable until there is an email, at least one lead and a mailbox that can send it, and for members without Send campaigns. Everything can be changed later.

A campaign that has not launched is a draft, and drafts live in your campaigns list. Closing the flow with anything filled in saves it as one, and so does Import new leads before it takes you to Contacts. Clicking a draft in the list reopens this flow where it still needs work, with everything you chose, so you can finish the steps (Cmd or Ctrl-click opens the campaign page instead, and members without Manage campaigns always get the page). Leads added to a draft directly, from its Leads tab or an import, count alongside its lists. Discard throws away a new campaign that was never saved, and Delete draft removes a saved one. A draft whose flow has branches or action steps, its own window for each day, or mailboxes picked one by one keeps those as they are; the flow shows them and sends you to the campaign's own tabs to change them.

A draft's Overview tab shows what it still needs (leads, an email, senders), each linking to the tab that fixes it, with Continue setup to reopen the flow and a Launch button once it is ready. Nothing sends until the campaign launches.

How the estimate works

The estimate simulates the campaign day by day against the mailboxes that would send it. It uses the same rules as the scheduler:

• each mailbox's own cap and the campaign's daily limit
• the warmup graduation ceiling, which starts a freshly warmed mailbox low and adds 5 a day
• the workspace's risk band and each mailbox's health band
• mailboxes on hold or failing domain authentication, which send nothing
• sending behaviour profiles
• the sending window, with the spacing between sends

Warmup keeps running on every warming mailbox, reduced to 5 emails a day while it backs a live campaign, and those emails use the same spacing clock as campaign sends. The estimate counts them, so a narrow window with a long gap between sends finishes later than the caps alone suggest. Mailboxes that already send for other campaigns keep that share of their cap, judged from their last seven days.

Follow-ups that are due go out before new leads start, and the total assumes nobody replies or unsubscribes, so real sequences usually finish sooner. Replies, bounces, new contacts joining a linked segment and changes to a mailbox's health all move the real finish.

Plain text only

Settings > Plain text only sends the campaign without an HTML part. Recipients get the plain-text body with the mailbox's plain-text signature, and because open pixels and wrapped links need HTML, open and click tracking are off for that campaign whatever their toggles say. Test emails respect it too, so what lands in your own inbox is what recipients get.

Senders and rotation

Pick mailboxes in Sending accounts three ways, and the first two combine:

• By tag: every active mailbox with that tag, including ones you tag later.
• Individually: specific mailboxes by hand.
• All active mailboxes: the default when you pick neither.

A campaign set through the API to sender_strategy: "explicit" is the exception to the third line: it never falls back to every active mailbox. If its list empties out, because the mailboxes were disconnected or the list was replaced with nothing, it uses any tags it also has, and with none it pauses itself rather than widening to every mailbox in the workspace. See replace senders.

Sending accounts always resolve inside the campaign's own workspace. If you belong to more than one workspace, a tag you reuse across them still only picks up mailboxes belonging to the workspace that owns the campaign, so one workspace's sending reputation, daily caps, and warmup are never spent on another's traffic.

Whichever mode you pick, it decides which mailbox starts a lead. Every mailbox still stays inside its own daily cap and minimum gap, so a campaign's volume is the sum of its mailboxes' budgets as always. Rotation only chooses among mailboxes whose minimum gap has passed, and warmup mail counts toward that gap. A mailbox that just sent warmup sits out that turn and another one starts the lead. The campaign only waits when every mailbox is inside its gap.

The Leads tab shows each lead's mailbox in its Sender column, and a contact's Activity tab shows it beside their progress. A lead has none until its first email goes out.

ESP matching optionally aligns sender and recipient providers (Google to Google, Microsoft to Microsoft). The recipient's provider is read from their domain's mail records, so a lead on a company domain hosted by Google Workspace or Microsoft 365 is matched too, not only gmail.com and outlook.com addresses; the contacts list shows it as a badge on each contact's avatar. A mailbox connected with an app password to Google Workspace or Microsoft 365 counts as that provider. Under Settings > ESP matching, the coverage panel shows how many of the campaign's leads are on Google, Microsoft and other providers, and which of your mailboxes serve each. Prefer same falls back to any mailbox when no same-provider one is free; Strict same makes the contact wait instead. A contact left waiting this way waits alone: the campaign moves on to the next lead in the queue rather than stopping, and comes back to them when a matching mailbox is free. An unknown recipient provider never blocks a send. Like rotation, it applies to a lead's first email: a follow-up goes out from the mailbox the contact already knows.

When a lead's mailbox is busy, or gone

Two things can happen to a lead's mailbox, and Warmbly treats them differently:

• Busy: it has used its daily budget, or it is outside its own sending hours. The lead waits for it, and the rest of the campaign keeps sending from the mailboxes that are free. Nothing is lost: the lead sends when the mailbox is next available, and the activity log notes the wait once a day.
• Gone: it was disconnected, removed from the campaign's sending accounts, sent to rest, held by warmup health, or its domain is failing authentication. Waiting would leave the contact silent for days, so the lead moves to another mailbox in the pool and the campaign's activity log records the change.

Removing a mailbox from Sending accounts therefore hands its in-flight leads to the remaining mailboxes as each of them reaches its next step. Adding a mailbox never moves an existing lead; it picks up new ones.

Sending limits

Warmbly is mailbox-first: safe volume is the sum of each mailbox's budget, not one global limit. Limits stack, and the smallest always wins.

The campaign daily limit applies as a minimum against the cold cap, so it can lower a mailbox's volume but never raise it above the mailbox's own daily cap (default 50/day).

Only an email actually handed to a sending worker counts against a mailbox's daily budget and its minimum gap. The scheduler's own wake-ups, a step it deferred because its slot was not due yet, and action or wait steps never do, so a campaign started outside its sending window still has its whole budget when the window opens. When every mailbox on a campaign has used its budget for the day, the campaign stays active and waits for the next day; the activity log notes it once per day, and it notes the send that used the last of the budget as well, so a campaign that sends one email in the morning and then goes quiet says so in its feed rather than looking stalled. It also waits, rather than pausing, when every mailbox is outside its own hours, resting, or held back by warmup health. A pool that is part spent and part asleep says so too, naming how many of each, because that campaign resumes when the sleeping mailbox reopens rather than tomorrow.

Each of those lines carries a breakdown per mailbox: the cap this campaign gives it today, which limit set that cap (the mailbox's own daily cap, the campaign daily limit, the campaign ramp, the easing out of warmup ceiling, or the workspace's risk band), how much it has sent, the gate that closed it if one did, and its warmup health band when that is dampening it. When a pool's day is shorter than you expected, this is where to look first: a mailbox that is still warming sends 5 cold emails a day at most, whatever its cap says, and three such mailboxes make a 15-a-day campaign.

Today's sending plan

The campaign overview opens with a one-line Today's sending plan: how many emails the campaign sends today, worked out through the same gates a real send goes through, and the one limit that decides it. Why opens the working: a list of every limit that took the number below what your settings add up to, the leads, and each mailbox's day. The card re-reads itself once a minute while the page is open.

For an active campaign the plan is worked out in the background and refreshed about once a minute, so opening it is quick no matter how many leads the campaign has. The card shows when the figures were last worked out. Right after you edit, start or stop a campaign, or just after midnight UTC, it shows the last good figures while a fresh plan is worked out, then updates on its own within moments. A campaign you have only just created is worked out the moment you open it.

The number is the sends already out plus what is still expected, and the list under it adds up: the mailbox caps added together, minus each limit, minus what has been sent, is what is still to go. A limit only appears when it removed something. In the order the scheduler applies them:

Under the list, the card says how many leads are due now, due later today, waiting on a step's delay, inside an undecided branch window, waiting for their own mailbox (each contact keeps the address they first heard from, so a follow-up whose mailbox is spent waits rather than switching) or held, and when the campaign next works through its queue. Daily budgets reset at midnight UTC whatever the campaign's timezone, so a campaign far from UTC sees its "sent today" reset partway through its own day. Expand the mailbox rows to see each mailbox's cap for this campaign today and which limit set it, what it has sent (for this campaign, and for others), what it is still expected to send, and whether it is sending, closed for the day, out of budget, resting, held, failing authentication or reconnecting (no running sending worker holds it right now; it is placed on one again within minutes and the other mailboxes keep sending meanwhile). Each limit links to the page where it is changed.

The sidebar's sent today meter reads its denominator the same way: what the workspace's mailboxes can send today under these limits, not their caps added up. The two agree by construction, because both are read through the scheduler.

Daily ramp-up grows volume gradually instead of starting at full limit: ramp start (default 10), ramp increment (default 5), and ramp ceiling (default 50). It applies as another minimum, so it only lowers today's volume while ramping. This is separate from mailbox warmup; the two work together.

Lead flow throttles new contacts with Max new leads per day (0 for unlimited, up to 1000). At the cap, follow-ups to in-flight contacts continue and new leads resume tomorrow. You can prioritize new leads over follow-ups, and choose whether to attempt addresses verification flagged risky.

Keep running for new leads turns a campaign into an ongoing one: when it runs out of leads it stays active and shows waiting for leads instead of finishing, then sends the sequence to each lead as they arrive from a linked segment, a form, the API, Zapier, Make, n8n or an automation. Linking a segment, pointing a form at the campaign, or saving an automation that enrols leads in it turns it on, and so does pressing play on a finished campaign whose every lead is done; turn it off in the campaign's preferences to have the campaign finish once every lead is done. A campaign with this on can be started with no leads yet. An end date still ends it.

Adding leads

The Leads tab takes contacts four ways. From contacts opens a picker over the workspace contact list: search by name, email or company, filter by label, tick individual people or Select loaded, or Select all matching to add everyone the search returns, up to 250,000 at a time (narrow the search and repeat past that). Contacts already in the campaign are marked as leads and skipped. Import runs the file import wizard with this campaign preselected (its Options step can also pin the file into segments), Sheet sync attaches a Google Sheet, and Add lead creates a single new contact in the campaign. Any workspace member with contact access can add leads to any campaign in the workspace, whoever created it.

Segments on the same toolbar links segments to the campaign as a live audience, up to 20 per campaign. Linking enrols every current member immediately and turns on Keep running for new leads, and contacts who enter a linked segment later are enrolled on their own, within a couple of minutes. An active campaign wakes to send to them (a campaign waiting for leads picks up straight away), a finished one restarts through the usual launch checks, and a paused one accumulates them for later. A contact who leaves a linked segment keeps their lead row, but detaching the segment itself takes its leads back out, so swapping one segment for another leaves the campaign with the new list rather than both. Leads the campaign has already emailed stay, as do any you added by hand and anyone a segment that stayed linked still covers; the dialog asks before a save that costs leads. See linking a segment to a campaign.

Every linked segment is shown in a Linked segments strip under the toolbar, so the audience feeding the list is always visible. Each chip names the segment and shows how many of its members are leads right now (120/120); clicking it filters the list to that segment's leads, and the arrow next to it opens the segment. A segment that matches no contacts says no contacts instead of a count, and one whose members were removed from the campaign by hand shows how many are held out with an Add back action, which re-enrols every current member and clears the removals. When a campaign has linked segments but no leads, the empty state explains why (the segments are empty, or their members were removed by hand) rather than offering to link a segment again.

Export on the toolbar downloads the leads as CSV, XLSX or JSON. The scope is the campaign: Every lead exports the whole list, Filtered the leads matching the current filters, Selected the ticked rows. The Campaign-ready column preset adds each lead's status and whether they opened, clicked or replied. The same export lives on a segment page for its members.

A lead can also be taken out again: the remove button on a lead's row, or Remove from campaign in the selection bar when several are ticked, drops the lead from this campaign without deleting the contact. The header checkbox covers the leads loaded so far, and the bar under it offers Select all matching when more leads match than are on screen. The removal sticks: a linked segment will not re-enrol that contact automatically, even while they still match it, until you add them back yourself. Neither offers to delete the contact itself: inside a campaign the destructive action is leaving the campaign, and deleting a contact from the workspace is done from the contacts list.

Lead statuses

A lead is Processing only while steps remain, so a finished campaign reads as done rather than stuck mid-flight.

Out of office and pausing one lead

When a recipient's mailbox answers a step with an away message, that is not a reply: Warmbly never counts an auto-reply as a human one, so stop on reply does not fire and, left alone, the next step would go out on schedule to an empty desk. Warmbly holds the lead instead, in every campaign that contact is still a lead of rather than only the one that was answered. An empty desk is an empty desk, so a contact you are running two sequences to is held in both. Completed campaigns are left alone, since nothing in them will send again.

The hold reads the return date out of the away message when it can. English, German, French, Spanish, Portuguese, Italian and Dutch phrasings are recognised (back on 8 September, zurück am 09.09.2026, ab dem 10.9., jusqu'au 12 septembre), in ISO and day-dot-month form as well as written months. German calendar weeks count too: ab KW 42 resumes from that week's Monday, bis KW 41 from the Monday after it. Two kinds of date are deliberately not read, because a wrong one parks a live lead for weeks: slash dates, since 9/8/2026 means two different days on two sides of the Atlantic, and a month with no day (until October), since there is no way to tell which day in it was meant. The lead resumes one working day after the date it found, so the follow-up does not land in the backlog of their first morning back. When no date can be read, the hold is the workspace's fallback, 7 days by default, set under Settings > Sending > Out of office. The same section turns the whole behaviour off.

With automatic inbox tagging on, the date gets a second reading. The phrase it came from is shown to the classifier, which is asked whether it says when the sender is back. When the answer is a clear no (the date is the first day of the absence, or a stand-in's hours), the hold uses the fallback instead, and the lead's reason reads auto-reply, return date unclear. An unsure answer, or a failed call, leaves the date as read.

A hold does not spend the step's wait. A follow-up three days behind its step, held for a week, goes out three days after the contact is back rather than the moment they return, so the sequence keeps its pacing instead of arriving all at once. Only the part of the hold that overlapped that wait counts, so a hold the lead has already served is never charged to a later step. A campaign whose remaining leads are all paused does not finish: it stays active and waits for them, and its activity log says so once rather than every pass. Resuming any of them puts the campaign straight back to work.

The same hold is available by hand, and it is the missing middle between leaving a lead alone and the two permanent levers. The Subscribed toggle takes the contact out of every campaign for good and the suppression list blocks the address workspace-wide; neither is the right answer to "they are on holiday for a week". The pause button on a lead's row holds that one contact in that one campaign, until a date or until you resume them. The same Pause sits on each campaign in the contact's Activity tab and in the unibox contact panel, so a reply can hold the follow-ups without leaving the thread. By hand it is one campaign on purpose, unlike the out-of-office hold: you are deciding about this sequence, not reporting that the person is away. They stay subscribed, they stay a lead, and the flow picks up where it stopped.

An away message is recognised by the subject line the recipient's mail provider writes (Automatic reply:, Automatische Antwort:, Abwesenheitsnotiz, Réponse automatique, and the same conventions in Spanish, Portuguese, Italian, Dutch, the Nordic languages and Polish) or by the RFC 3834 and vendor headers it carries. It is matched at the START of the subject only, never inside it: a reply from a person carries your own subject back, so a campaign about annual leave or working out of the office still has every human reply read as a reply.

A held lead reads Paused in the list and carries its reason on hover. Open the contact's Activity tab and the campaign panel shows the hold with Resume now next to it, and Stop, which converts a dated hold into one with no end. A lead with a step still to send gets Pause lead there instead; one whose flow has ended has neither, because a pause would change nothing. Resume drops the held time rather than carrying it, so the step goes back to the schedule it would have had if the hold had never happened: on the campaign's next pass when that moment has already passed, otherwise when the step's own wait elapses. It lifts the hold, it does not skip the sequence's pacing. Pausing and resuming are audited, and every teammate's list updates live.

Copying colleagues on one lead

Reaching two people at one company as two separate leads gives each their own thread and their own follow-ups, neither aware of the other, which reads as double outreach. Copy the second person on the first lead's emails instead. Open the lead's contact, go to Activity, and use CC a colleague on that campaign's card. The picker offers the lead's likely colleagues first (contacts with the same company name, or the same email domain when it is a company's rather than a personal mail service like Gmail or GMX), and searches the whole contact list as you type. A copy is always a contact in the workspace, so suppression, bounces and verification apply to it exactly as to a lead.

Every email the campaign sends that lead carries the copies in CC, follow-ups included, so the whole conversation stays in one thread. It is per campaign on purpose: copying someone on a lead in one campaign does not copy them anywhere else. A lead can copy at most 2 contacts. Every copy is one more recipient who did not ask for the email, so this suits small, personal campaigns better than volume sending. It does not change how much the mailbox sends: the email still counts once against its daily cap and spacing, though Google and Microsoft count each copy toward the mailbox's own recipient limits. Leads with copies show a CC badge in the Leads list, with the addresses on hover.

What happens to the people on the thread:

Opens and clicks are counted per email, not per person, so a copy opening the email or clicking a link counts toward the lead.

A contact copied on a lead is reached in that lead's thread, so if they are also a lead of the same campaign their own sequence is held with the reason Copied on the emails to the lead's address. That hold has no end and does not keep the campaign from finishing. Removing the copy, or removing the lead from the campaign, releases it and their own sequence picks up. Send their own too on that hold starts it anyway after asking, for when two threads are really what you want. For the same reason a lead that is copied on someone else cannot copy others, and a contact with copies of their own cannot be copied.

The campaign's own CC and BCC in its preferences go on every email to every lead. Both kinds of copy skip an address that is suppressed or is the lead's own, so a copy never reaches someone the lead's email could not have. A campaign-wide address that bounces on one of the campaign's emails is left off its later emails, so one bad address cannot fail every lead's send; fix or remove it in the preferences.

Who opened, clicked and replied

Next to each lead's status, the Leads list shows three engagement columns: Opened, Clicked and Replied, each with the number of emails in the sequence the person engaged with. A dash means the lead was emailed and has not engaged; the cell is blank for a lead not emailed yet. An open counts when a person opened the email, or clicked a link in it. Mail clients that fetch every image automatically (Apple Mail Privacy Protection, for example) show as auto instead, the same opens the campaign overview reports as automatic, so they never pass for engagement. Clicks are held to the same standard: a link followed from a known mail security network, within the instance's automated-click window after the send (thirty seconds by default), or several links of one email followed within a few seconds of each other, is a security gateway scanning the message, not the recipient. Those clicks are kept on the contact's activity marked auto, counted apart on the campaign overview, and never make a lead Clicked, never fire a clicked branch or automation, and never send a webhook. See Link tracking and UTM parameters.

Opens depend on the recipient's mail client loading images. Outlook, many corporate setups and some privacy-minded clients block them, so a person can read an email and still show no open; the info icon on the column says as much. A click is stronger evidence, so a click by the person always counts as an open too. Open the contact's Activity tab to see each open and click with the device, mail client and location it came from, for example iPhone · Apple Mail app or Gmail · device hidden (Gmail and Apple Mail Privacy Protection load images on the reader's behalf, so the device cannot be known). See How an open was read.

The chips above the list are filters. Click a status chip (Processing, Done, Replied, Queued, Bounced, Paused, Unsub) or an engagement chip (Opened, Not opened, Clicked, Not clicked, Replied, Not replied) to show only those leads; click it again to clear. One status and one engagement chip can be active at once and both must match. The numbers on the chips are campaign-wide totals, and filtering happens on the server, so a scope shows every matching lead however long the list is. Not opened, Not clicked and Not replied only cover leads that have been sent at least one email: a queued lead has not had the chance. The same filters live in the Filters sheet under Lead status and Engagement.

Engagement updates live as opens, clicks and replies arrive; no refresh is needed. Export from the Leads tab offers four extra columns (Lead status, Opened, Clicked, Replied), whether you export the current scope or selected rows.

What one lead is doing next

Open a contact and go to Activity: the panel at the top lists every campaign the contact is in, with the flow drawn step by step (sent, opened, clicked, replied, bounced or failed on each), the lead status, the last thing that happened, and the next action.

The next action is worked out on the spot by the scheduler, through the same rules a real send goes through: the delay before the first email, the step's wait, the campaign's start date and sending windows, each mailbox's daily cap and spacing, and the new-lead limit. Nothing is stored per contact, because a campaign is a single task that picks the next lead each time it runs. The times it shows are the constraints themselves, never the send spacing, so reading the panel twice gives the same answer twice. So the panel shows one of:

When a step's branches are still undecided (if they open within 3 days), the panel says the next step depends on their response and when that window closes. A lead that has finished, bounced, failed or unsubscribed shows why the flow ended instead, as does a replied lead that stop on reply ended. A replied lead the campaign still routes (stop on reply off, or a reply branch) keeps showing its next step.

One lead that cannot be sent right now never holds up the campaign. Each pass walks the queue in order and sends the first lead it can place, so a contact waiting for a same-provider mailbox, for the mailbox their conversation belongs to, or for their own working hours is skipped for that pass while the leads behind them go out. A pass tries up to 200 due leads this way. The campaign only waits when every lead it looked at is waiting, says so once a day in the activity log, and comes back and looks again within fifteen minutes.

A step counts as sent only once the sending worker has handed it to the mailbox provider. If the worker cannot send (the mailbox was still loading, the provider refused the message, a storage hiccup), the step goes back to the queue, the failure appears in Needs attention with the reason, and the next pass retries it. A mailbox that no running sending worker holds is passed over rather than picked, and a pass that fails for any reason is followed by another about a minute later, so a failure never leaves a campaign's leads queued until it is restarted. After five failed attempts the lead is marked Failed and dropped from the campaign, so a mailbox that can never send does not loop forever. A recipient the mail server refuses outright is not retried: it is recorded as a Bounced lead straight away and goes through the same bounce handling (suppression, guardrails, webhooks) as a bounce notice. A campaign that finished while a send was still in flight reopens to retry it.

Every sent count counts emails only: the contact's Sent total, a lead's sent steps, the campaign's progress and the rates its guardrails judge. Wait, condition and action steps move a lead through the flow but send nothing, so a lead is Done once every email step has gone out, however many other steps sit between them.

No contact is emailed the same step twice. Each step is recorded as attempted before the send is handed to a worker, so a crash, a restart, or a database hiccup in the moment between the two cannot make the step look unsent and send it again. The trade-off is a step whose outcome is genuinely unknown, when the worker stops responding mid-send: after 30 minutes with no answer the step is treated as a failed attempt, appears in Needs attention, and is retried like any other failure.

Link tracking and UTM parameters

With Link tracking on, every link in the email body becomes its own tracked link, so Warmbly records which link was clicked, not only that one was. Open a contact's Activity tab and a click reads Clicked Pricing, with the campaign, step and sending mailbox on the row and, expanded, the link's text, its full URL, every UTM parameter it carried, the browser, and whether a person or a scanner followed it. The campaign's live feed names the link the same way, and the campaign.email_clicked webhook carries the URL and the link text.

UTM parameters (on by default for campaigns created in the dashboard, off for campaigns created through the API unless you send utm_tracking) tag every link when the email is sent, so nobody has to add them by hand and clicks show up attributed in your web analytics:

A link that already carries one of these keeps the hand-written value; only the missing parameters are added. Existing query strings and fragments are left exactly as written, and the tags go on the real destination, so they survive the tracking redirect. Anchors, mailto: and tel: links, and anything that is not http(s) are never touched. UTM tagging works with link tracking off too: the tags are added and the link is otherwise left as written. Bare URLs in the plain-text part are tagged as well, numbered link_1, link_2 since they have no text. Change the source, medium and campaign values under Settings > Deliverability; leave a field empty to use the default.

Scheduling

Campaigns send only inside the weekly sending windows you define, in the campaign's timezone. Each day is independent, with different hours or several windows per day, set from presets like Mon-Fri 9-5 or by dragging on the grid (which is Monday-first).

A new campaign follows the workspace timezone, set under Settings > Profile > Timezones (which also lists every campaign's and mailbox's timezone, each changeable there in one place), until you give it one of its own on its Schedule tab; while the workspace has no timezone, the wizard starts from your browser's instead. A campaign created through the API without a timezone follows the workspace too and reports the zone in use as effective_timezone. Check the zone when a campaign is meant for another region: an 8am to 6pm window is read in that zone, so a campaign started in the morning in New York on a London schedule has already used most of its day.

A step whose turn comes while the window is shut waits for the next one; it is never sent late to catch up. That holds however overdue it is, so a follow-up whose wait elapsed at two in the afternoon does not go out at eleven at night because the campaign happened to look at it then. The step keeps its place in the queue and leaves in the next window that has mailbox capacity.

Within a window Warmbly spreads the day's emails evenly, adds random jitter, and rounds to natural send times so nothing arrives in obvious bursts. A mailbox with its own timezone is also kept inside its local business hours (8am to 8pm).

The spread covers every mailbox on the campaign, not one at a time: the day's remaining capacity across the whole sending pool is paced across the hours left in the window. Adding a second healthy mailbox roughly doubles how fast a campaign works through its leads, while each mailbox still stays inside its own daily cap, hourly ceiling and minimum gap.

The spacing sits between sends, never in front of the first one. A campaign you start (or resume) with a lead due sends that lead as soon as one of its mailboxes can (inside the sending window, under its daily cap and past its minimum gap), and the paced gap only begins once that email has gone.

When nothing is due (every lead is inside a step's wait, for example), the campaign re-checks itself at least every 15 minutes rather than sleeping until the next step falls due; the activity log notes it once a day rather than on every check. Leads added to a waiting campaign are sent on the same terms, without waiting for that re-check or a restart, unless the campaign sets a delay before the first email. Leads added while a campaign is mid-send join the queue and go out at its current pace, so adding leads never shortens the gap between two sends.

Delay before the first email

By default a contact's first email is due the moment they enter the campaign. The campaign's Settings > First email holds it back instead: choose After a wait, then pick a preset (1 hour, 4 hours, 1 day, 2 days, 3 days, 1 week) or a custom amount in minutes, hours or days, up to 90 days. The same control sits on the Trigger card at the top of the Steps canvas, and both write one setting.

The delay counts from when that contact entered the campaign, not from when the campaign started. A contact who joins a linked segment three weeks after launch still gets the full delay from their own arrival, which is what makes it useful for a campaign that keeps enrolling people. Once the delay elapses the email goes out in the first sending window that has mailbox capacity, exactly like any other step, so a 2 days delay on a Friday afternoon lands on Monday morning if you only send on weekdays.

Follow-up spacing is separate and unaffected: that is each step's own wait, set on the connection into it (see Sequences). Every lead carries the moment it was enrolled, so turning a delay on does not re-delay people who joined weeks ago: their wait is already long past. Leads enrolled before this setting existed have no recorded moment and fall back to the campaign's creation date, which has the same effect. Changing the delay on a running campaign takes effect on save.

Optional campaign dates bound when it may send. Leave both blank to run open-ended. Picking today as the start date means "start now", and clearing a start date on a running campaign removes the wait entirely. Schedule changes on an active campaign take effect immediately: the next send is recomputed on save, so a campaign waiting on a future start date starts sending as soon as you clear or shorten it. Past the end date nothing goes out at all, including a follow-up that came due before it: the campaign finishes instead, and its activity log says it reached its end date.

Start and stop

The play and pause buttons work from the list row or the detail view. Starting moves the campaign to active and begins scheduling inside your windows and limits; pausing stops new scheduling immediately and resumes from where it left off.

A campaign can pause itself: paused, no accounts when it loses every sender or no sender can send under its settings (a sending behaviour profile with no working days), paused, trial expired when a trial ends, auto-paused when a guardrail trips, needs verification when address verification has refused every remaining lead (the campaign offers to re-verify them or send anyway; see address verification), and plain paused if it ever loses its workspace, because unsubscribes, bounces and complaints are checked per workspace and cannot be honoured without one. It moves to finished once every contact completes the sequence or its end date passes, unless Keep running for new leads is on: then it stays active and shows waiting for leads until the next lead arrives, and only its end date finishes it. Configured to do so, it also stops following up with a contact the moment they reply.

An auto-pause is never silent. It writes a red entry to the campaign's activity log saying which of the several possible causes it was, and every teammate's campaign list moves to the paused status live, so a campaign that stops sending overnight is visible the moment anyone looks at it rather than hours later.

A finished campaign starts again on its own when a lead is added to it, whether by a linked segment, the API, a form, an integration or an automation, through the same launch checks as pressing play. If a check refuses the restart (the list is a bounce risk, the plan cannot send, too many campaigns are active), the activity log says so and the new leads wait until you fix the cause and press play. Pressing play also works after extending or clearing the end date. If there is genuinely nothing left to send, pressing play turns on Keep running for new leads and the campaign stays active, waiting for leads, so it never dead-ends on a campaign that only ran out of people to write to; the activity log notes the switch.

Duplicate and delete

Every campaign has a ⋯ menu, on its row in the list and in the header of its detail view, with Edit, Duplicate, Start or Pause, and Delete. Both actions need the Manage campaigns permission; a member without it is told which permission is missing instead of the action failing later.

Duplicate creates a new draft from the campaign's configuration and opens its settings so you can rename it (it starts as name (copy)), pick a different audience, change the copy, or adjust the schedule before starting it. The copy keeps every setting, the steps with their branching, the sending accounts, folders, tags, A/B variants and attachments. It does not keep leads, progress, statistics, activity, the ramp level, an auto-pause, or a start or end date that has already passed. The original is not touched, and the two campaigns are independent from then on. A duplicate counts as a new campaign for the daily creation limit.

Delete asks for confirmation that spells out what goes: the campaign, its steps, lead progress and activity. Contacts and emails already sent stay. A running campaign can be deleted directly; the confirmation says so, and sending stops immediately because every task waiting for the campaign is cancelled together with it. The same action is available at the bottom of the campaign's Settings. Deletion cannot be undone.

Auto-pause guardrails

Preferences > Opt-out line chooses what this campaign appends after the signature: the workspace default from Settings > Sending, a reply-to-opt-out sentence, an unsubscribe link, or nothing. Unsubscribe header attaches the RFC 8058 headers alongside. See unsubscribe and suppression.

Preferences > Auto-pause stops a campaign the moment its rates leave the band you set, instead of waiting for a mailbox provider to react. Off by default.

Two more controls keep the rules honest:

• Only after is the sample floor. No rule fires below this many sends in the window, because one bounce out of four is not a 25% bounce rate. Default 50.
• Measured over the last is the rolling window in days. 0 measures the campaign's whole history. Default 7.

Setting a rate to 0 turns that rule off. The check runs every 15 minutes, and when several bands are breached at once the campaign is paused with the most damaging reason attached: complaints first, then bounces, then replies.

A paused campaign shows the reason and the numbers behind it on the Auto-pause section, and everyone on the team who can see campaigns gets a notification. Starting the campaign again clears the marker, but the next check re-evaluates from scratch, so fix the underlying problem first.

Live activity

The detail view streams sends, opens, clicks, replies, bounces, and skips as they happen, for every teammate at once. The Sending card appears only while an email is actually being handed to a worker, and always names the contact; between sends the panel shows the campaign's progress and the log, not a send in flight. A Needs attention panel above it surfaces failures such as a step that could not be scheduled, a send the worker could not complete, or a mailbox whose sending worker is offline; these retry automatically and stay visible so nothing fails silently.

If scheduling stalls on a transient infrastructure hiccup, Warmbly re-seeds within a few minutes. Pausing and resuming forces a fresh start.

Content checks

Warmbly scores each step's copy out of 100 for the signals spam filters weight: trigger wording, stacked punctuation, ALL-CAPS subjects, link and image counts, image-only bodies, empty or oversized bodies, and attachments.

Anything the checker can point at, it points at: the badge names the subject or the body (or both, when the wording straddles the two), the offending words are quoted back exactly as you typed them, and the line they sit in is shown for context. You never have to hunt through your own copy for a word the checker already found.

A few issues are about the message as a whole rather than any wording in it. An empty subject, an empty or oversized body and an image-heavy layout name the half they concern but have nothing to quote; an attachment on a cold email concerns neither half, so it shows as a plain line with no badge. Every issue, located or not, carries its fix in a sentence.

You see it in three places:

• In the editor, re-scored as you write a step.
• In the launch dialog, alongside the other pre-send checks, with the lowest-scoring step named and its worst issue quoted as Subject: or Body:. Only email steps are scored; wait and action steps carry no copy.
• In the campaign activity feed, if the copy that actually goes out scores below your floor, again naming the half of the message at fault.

That last one catches what the first two cannot. The editor scores the template; the send path scores the message after merge fields, spintax, A/B selection and AI blocks have resolved, which is where a clean template becomes "Hi ," or picks the one spammy spintax branch. It logs once per step per day, not once per recipient.

Settings > Sending > Content checks turns it off or moves the floor, which defaults to 60 and accepts 1 to 100.

Analyze with AI

The rules above catch what rules can catch. Analyze with AI, under the score in the step editor, reads the copy itself and reports what a filter and a human reader will object to:

• the specific word, phrase or sentence, quoted from your draft, and whether it is in the subject or the body
• why that fragment hurts deliverability or replies
• what to write instead
• a rewritten subject line, which you can apply in one click
• copy-level advice that has no single fragment to point at
• an overall deliverability score out of 100

It runs on the AI provider configured for the deployment (see AI credits for the cost, and Configuration for self-host setup). It needs the Use AI permission. A deployment with neither an AI provider nor TypeSafe configured says so in place of the button rather than offering something that cannot run.

When the deployment has TypeSafe configured (TYPESAFE_API_KEY), the same click also returns a Reads as block: how the copy lands with the person receiving it, on a personal-note-to-bulk-mail scale; whether it is written for this reader or could be sent to anyone; whether it makes one clear ask, several, or none; and a warning when it makes a claim a spam filter would object to. These are calibrated numbers from a reader model, not prose, and the subject and body are sent to TypeSafe to get them. On a deployment with TypeSafe and no AI provider, the button still works: it returns the rules score, the Reads as block and a one-line reading in place of the quoted findings, and spends no credits.

Every quote is checked against your draft before it is shown. A fragment the model could not have copied from your copy is dropped rather than displayed, so the panel never points at a sentence you did not write.

Re-check

Re-check re-scores the copy on the spot instead of waiting for the editor's debounce, and once you have run an AI analysis it re-runs that too. Edit what the findings told you to edit, press it, and the panel shows the new score against the previous one: +14 since your last check.

The AI score is deliberately not sampled, so re-checking copy you did not touch returns the same number. A change in the score is a change in the copy.

When the draft has moved on from the analysis on screen, the panel says so and highlights the button, rather than presenting stale findings as current.

Testing placement

A content score reads the copy; a placement test sends it. Test any email step from Placement tests by choosing the campaign and the step: the copy is rendered the way this campaign sends it (merge fields for its first lead, its opt-out line, its tracking and attachments) and sent from one of its mailboxes to seed inboxes at the major providers, which report whether it reached the inbox, a Gmail tab or spam, or never arrived. Each copy is a send from that mailbox's daily limit.

A placement monitor repeats that on a schedule while the campaign runs, every 7 days by default, rotating through the campaign's mailboxes. When a run lands below its alert threshold (70% inbox by default), everyone who can view campaigns is notified, and the monitor can pause the campaign too, as an auto-pause you restart yourself. See inbox placement tests.

Easing out of warmup

A mailbox that has been warming does not jump straight to its full cold cap. Going from 40 warmup emails a day to 50 cold emails the next morning is the volume jump mailbox providers penalise, so Warmbly ramps into it.

The mailbox starts at a volume set by how long it warmed, then adds 5 a day until it reaches the cap you configured:

The ramp only ever lowers a cap, never raises one, so your configured limit and the campaign's daily limit still bind. A spam placement at Google, Microsoft or Yahoo pauses the climb for the same three days it pauses the warmup ramp, and the paused days are subtracted rather than made up. The mailbox drawer shows today's allowance and roughly when it reaches your cap.

The launch check on your list

Starting a campaign measures its recipient list first and refuses to launch one that is known to be largely undeliverable. Mailbox providers put a sender under review at around a 5% bounce rate, so the number worth seeing is the one you can see beforehand.

What it counts:

• Known-invalid addresses only. Verification has to have actually rejected the address. A list nobody has verified is not evidence of a bad list, so it is never blocked on that basis, only pointed out.
• Deliverable recipients only. Suppressed and unsubscribed leads are skipped at send time, so counting them would make a bad list look fine.
• Lists of at least 50. Below that a share means nothing, and no launch is refused on it.

A refused launch shows why and offers Launch anyway, for a list you verified with another service. Through the API the same override is acknowledge_list_risk on the start request.

Above 4% projected bounce the launch is refused with the number and what to do about it. Between 2% and 4% it launches with a warning. The same projection appears in the launch dialog before you click, so a refusal is never a surprise.

Safety posture

Defaults are deliberately conservative, aiming at a low complaint rate rather than maximum throughput:

• Spacing over bursts: the minimum gap and even distribution keep a natural cadence.
• Spread, don't concentrate: volume splits across many mailboxes and worker IPs.
• Ramp gradually: raise volume only while performance stays healthy.
• Health gating: a mailbox in deliverability trouble has its cold volume cut or paused automatically.
• Human timing: mailboxes with sending behavior enabled keep randomized working hours, volume, and spacing in their own timezone.

A practical band is 30 to 50/day for warmed mailboxes, starting newer ones at 10 to 20.

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