Mailbox statuses: Active, Warming, Paused, Disconnected, Unverified

How to do it

1. Open Mailboxes and read the pill next to each name. Hover a Paused, Disconnected or Unverified pill to see why — for example the last connection error.
2. Use the Status filter to show only Active, Paused, Disconnected or Unverified mailboxes, or the ones that need action; the count beside each option tells you how many match.
3. To pause a mailbox by hand, open its row's ⋯ menu → "Pause Sending", or click "Pause Sending" at the top of its page. To pause several, tick them and click "Pause Sending" in the selection bar.
4. To send from it again, use ⋯ → "Resume Sending", "Resume Sending" on its page, or "Resume" in the selection bar.
5. "Recheck Connections" above the list checks the connection of every mailbox shown except paused ones and reports "Rechecked: N connected, N failed" — a mailbox counts as connected only when its SMTP check passed.

Good to know

• Active — the SMTP login succeeded; the mailbox is in the sending pool. Health 80, or 100 once its first warmup email has gone out.
• Warming — an Active mailbox whose warmup is on and can actually run (it has IMAP and a daily volume above 0) that hasn't sent its first warmup email yet, or whose daily ramp-up still holds it below its warmup volume. It sends campaigns like any Active mailbox. With warmup on but no IMAP, or at 0 a day, it shows Active and its Warmup column says why ("Needs IMAP to warm", or "0/day").
• Paused — held out of sending: no campaign email (manual email tasks included), warmup or test email goes out from it. Replies and forwards you write in Replies — and replies Claude sends with send_reply — still go out from it, each taking a slot of its daily limit. Its inbox is still read, so replies, bounces and out-of-office notices to the emails it already sent keep arriving. A mailbox is paused by hand (Pause Sending) or with its whole domain from Deliverability (a domain's Pause in the Sending Domains tab, or Pause N Critical Domains on a Needs Action card); hover the pill to see which. Health 40.
• While a mailbox is paused, campaigns keep sending from their other mailboxes, and follow-ups to people it already emailed go out from another of the campaign's active mailboxes. A campaign whose only chosen mailbox is paused waits until you resume it. (Deleting that mailbox instead pauses the campaign until you pick another.)
• Resume works on any paused mailbox, however it was paused — including one paused with its domain from Deliverability — and puts it straight back to Active. The one exception: if a connection check failed on its credentials while it was paused, Resume marks it Disconnected instead of sending from a mailbox known not to connect. Such a mailbox shows "Last check failed" beside its health (hover the Paused pill for the error), and the Resume tooltip counts how many would go to Disconnected — reconnect it first. Resuming its domain on Deliverability, for a mailbox paused that way, applies the same rule.
• A connection check never un-pauses a mailbox, whether it passes or fails: Recheck Connections skips paused mailboxes, and checking a paused mailbox (Reconnect on its row or its page) records the result but leaves it paused ("It connects. It stays paused until you resume sending."). Re-importing it by CSV, or signing in again with Google or Microsoft, stores the new credentials and re-checks them — and it stays Paused too.
• Pause Sending, Resume and Turn On Warmup in the selection bar only change mailboxes in the right state (Pause: Active; Resume: Paused; Turn On Warmup: Active with warmup off), and the result says how many were left as they were.
• Unverified — imported but never successfully connected; nothing is sent from it. Health 50. The background check picks these up every 5 minutes.
• Disconnected — the last check or send failed with a genuine credential or account problem. It is skipped when sending until it passes a check again. Health 42 minus 6 per repeated failure (never below 8). "Reconnect" (row ⋯ menu, or its page) signs in with Google or Microsoft again for a mailbox connected that way, and otherwise runs the connection check again.
• Only SMTP decides Active vs Disconnected. A failing IMAP check is recorded in the error text but does not disconnect the mailbox — it just means replies/bounces can't be read from it.
• A temporary network or proxy blip never flips a connected mailbox to Disconnected; only credential/account failures do. Those temporary errors are re-checked automatically every 8 minutes until they clear; credential failures are re-checked every 2 hours up to 12 times (about a day), then wait for you to click Reconnect or Recheck Connections.
• Recheck Connections checks 6 mailboxes at a time and shows its progress on the button ("Rechecking 12 of 40…").
• Replies are read from Active, Paused and Disconnected mailboxes (a disconnected mailbox's inbox is usually still reachable); not from Unverified ones.
• Campaign sends (manual email tasks included) and test sends refuse any mailbox that is not Active. Replies and forwards sent from Replies go out from an Active or a Paused mailbox, and are refused ("Mailbox is not active.") from a Disconnected or Unverified one.