We send an alert — or a list of mailboxes in your weekly check-in — when the warmup activity we observe on a mailbox is lower than we recommend. If you open the mailbox in your warmup tool and see a healthy target, the alert isn't contradicting you — it measures what the mailbox is actually doing, not the number in the settings.
Settings vs. actual activity
The number in your warmup settings is a target — the maximum warmup emails per day.
The alert is based on the warmup emails actually sent and received over the recent period.
Our recommendation for Maildoso SMTP mailboxes is 80 warmup emails per mailbox per day from day one, with slow ramp-up / increment per day disabled (50/day in tools that cap at 50, such as Plusvibe and EmailBison). A mailbox running below that is what triggers the alert. See How warmup works and how to start it.
Google Workspace mailboxes are the exception: they warm at 25/day with an increment of 2–3 per day, so a Workspace mailbox climbing towards 25 is expected.
Common reasons real activity is lower than recommended
Slow ramp-up (increment per day) is enabled in the warmup tool, so a new mailbox is climbing from a low number instead of starting at 80. On Maildoso SMTP mailboxes this is not needed — warmup should run at 80 from the first day.
The target itself was set below 80 — for example a sequencer's default of 20–50/day was left in place.
Warmup was paused, or the mailbox was disconnected from the warmup tool at some point and needs reconnecting.
The mailbox's domain finished provisioning only recently, so warmup started later than the other mailboxes in the batch.
Warmup is run in an external tool whose own schedule or throttle is lower than the target.
What to do
Look at the actual per-mailbox numbers in the list we sent (or in your tool's warmup statistics), not just the target in the settings.
Disable slow ramp-up / increment per day and set the target to 80 (or the tool's maximum). Do this right away, including on mailboxes that are less than two weeks old — there is no ramp-up phase to wait out on SMTP mailboxes.
If a mailbox shows as disconnected or has stopped sending warmup, reconnect it in the tool.
"My tool caps warmup at 50" is not the reason a mailbox is flagged. Mailboxes we flag are almost always well below 50 — for example 10, 20 or 40 a day. Raise them to the cap first; the cap only matters once you are already at it.
While warmup is below the recommendation, keep campaign sending at or below 15/day per mailbox (10/day in tools capped at 50). Low warmup combined with high campaign volume is the most common cause of the deliverability problems we see, so lower the campaign side rather than leaving warmup low.
Don't push the target above 80 to compensate for lost days — 80 is the ceiling for SMTP mailboxes; total sending is capped at 100/day.
If it still doesn't add up
Send us the affected mailbox addresses, the warmup tool you're using, and the daily volume you're sending in campaigns. We'll review your specific case and tell you whether the settings need changing or something is genuinely wrong. If your sequencer disabled warmup entirely rather than just flagging it as low, see My sequencer disabled warmup and asked for a reactivation code.