Warmup gradually builds your mailboxes' sending reputation before you start cold outreach.

Once your mailboxes are set up, warmup ramps the daily volume up over roughly two weeks so the mailboxes build a healthy history before you scale into real campaigns. Keep warmup running continuously — pausing it interrupts that reputation-building.

Yes. Buying mailboxes does not automatically start warmup, and Maildoso does not run a background or managed warmup pool on your behalf. Warmup runs through the sequencer you connect your mailboxes to (for example Instantly or Plusvibe — both have good warmup pools). Turn warmup on inside that tool and keep it running.

A safe target once mailboxes are ready is around 80 emails per mailbox per day total — for example ~50 warmup + ~30 outreach — rather than maxing out a single mailbox. See What's the daily email limit per email account? for the exact limits.

If a third-party tool (Mailivery, Mailwarm, etc.) reports a high spam percentage on mailboxes that have only been warming up and have sent zero campaign emails, the most common cause is a weak warmup pool in that tool — not a problem with your domain or mailboxes.

Two things to keep in mind: (1) our dashboard reputation and a single third-party seed-list placement test measure different things, and a one-off test is a snapshot that can vary; (2) Gmail is much stricter than Outlook, so a weak pool often shows up as poor Gmail placement specifically. If you're seeing this, switch warmup to a stronger pool such as Instantly or Plusvibe at roughly 50–80/day — placement typically recovers within a few days. If it persists, contact support so our deliverability specialist can review the account.

The older Premium AI Warmup add-on is no longer offered to new accounts and is not being applied to mailboxes. If your dashboard shows a premium-warmup flag you can't interact with, treat it as inactive and warm your mailboxes through your sequencer as described above.

For questions about whether your warmup is performing well (inbox placement, reply rates), contact support so our deliverability specialist can review your account.

📹 How to Scale to 100K Emails/Month Without Killing Deliverability — how teams set up infrastructure, warm mailboxes, and spam-test to scale volume safely.