Sequencers like Instantly sometimes ask for a code sent to your mailbox — either a verification code when you connect or reconnect a mailbox, or a reactivation code after they pause warmup. In both cases the code is sent by the sequencer to the individual mailbox; we can't generate or resend it.
Where the code goes and how to read it
The code arrives in the specific mailbox the sequencer is checking — not in your Master Inbox (codes aren't forwarded there). To read it, connect that mailbox to an email app over IMAP (for example Outlook or BlueMail, the same way you connect the Master Inbox — see Using your Master Inbox and connecting mailboxes to an email app) and open the message there. You'll find the mailbox's login details in a fresh CSV export (Email accounts → Export accounts → Download selected accounts as CSV).
If you're connecting many mailboxes, you can also ask Instantly support to lift the code requirement.
If your account can't request a verification code at all, contact us — we can have it reactivated from the backend.
For a Google Workspace mailbox's own sign-in code, see Logging in to your Google Workspace mailboxes.
Warmup disabled: "negatively impacting other users in the pool"
If your sequencer suddenly turns off warmup on a mailbox with a message like "negatively impacting other users in the pool", this is a safety mechanism of that sequencer's own warmup network — not a Maildoso account flag, and not a sign that your mailbox or domain has a real deliverability problem.
Warmup tools connect thousands of mailboxes from many providers into one "warmup pool" so accounts can send test emails to each other and build reputation.
To protect that pool, the tool automatically pauses mailboxes it thinks are behaving unusually — for example sending too fast, or receiving too many replies marked as spam within the pool.
This decision is made entirely inside the sequencer's network, separately from your Maildoso mailbox's actual sending health.
What to do
Look for the reactivation link or code in the mailbox (as described above) or in the sequencer's dashboard — most tools send one automatically and reactivate the mailbox once you confirm it.
If you don't see a code, check the warmup tool's help center or support — reactivation is handled entirely on their side.
Once reactivated, don't suddenly increase warmup volume — sudden jumps are a common trigger for another pause. Our recommended settings are in How warmup works and how to start it.
If this keeps happening across many mailboxes at once, or reactivation doesn't work, contact us with the affected mailbox addresses and the sequencer — we'll check whether anything on the Maildoso side needs attention.
Getting a "low warmup" alert instead? That's a different signal — see I received a "low warmup" alert but my warmup settings look correct. Other connection problems: Troubleshooting sequencer connection errors · Connecting your mailboxes to Instantly.