Re-test a mailbox connection

Re-runs the connection test against the stored credentials and updates the mailbox status. Rate limited. The mailbox status reflects the SENDING side only — a problem reading the inbox is reported in test_result.read_channel and never stops the mailbox from sending.

Required scope: mailboxes:write.

Subject to a stricter per-endpoint connection-test rate limit (in addition to the workspace-wide per-minute limit for your plan — Pro 60 · Enterprise 240 · Ultimate 480).

read_channel.state is one of ok | auth_failed | blocked_by_provider | not_tested. not_tested means we could not run the read test (for example a mailbox connected by sign-in rather than by password, which stores no reading password) — it is NOT a failure and NOT a pass.

imap_ok is true only when the read test actually passed, so it is false for a not_tested result. Read read_channel.state when you need to tell those two apart.