Microsoft 365 mailbox asks to reconnect
A Microsoft 365 mailbox renews its sign-in by itself; it needs Reconnect only when Microsoft refuses, and the message says why.
A mailbox connected with Sign in with Microsoft keeps itself signed in: you do not need to reconnect it on a schedule. Short hiccups at Microsoft (busy service, throttling) fix themselves and do not need you. It needs Reconnect only when Microsoft has really ended the sign-in.
What you see
The mailbox shows Disconnected or Messages: Not arriving on Accounts (/app/channels), and the reason reads like "Microsoft sign-in failed (400, AADSTS50173): the password was changed or reset, which ends every sign-in made with the old one. Sign in to the mailbox again from Accounts." The bell's Social account needs reconnecting notification gives the same reason in plain words.
The reasons and what to do
- "the password was changed or reset..." (AADSTS50173): reconnect and sign in with the new password.
- "the password has expired and must be changed" (50055): change the password at Microsoft, then reconnect.
- "the account is disabled in Microsoft 365" (50057): your Microsoft 365 administrator must re-enable the account, or connect the mailbox with another account that can open it.
- "the account is locked after too many wrong passwords" (50053): wait or ask your Microsoft 365 administrator to unlock it, then reconnect.
- "the user name or password is wrong" (50126): reconnect and check the account you sign in with.
- "the sign-in was not used for 90 days and lapsed" or "the sign-in has expired" (700082, 70008, 700084): reconnect.
- "Microsoft now requires multi-factor authentication for it" (50076, 50079): reconnect and complete the MFA prompt.
- "a security check (conditional access) must be completed" (50158) or "a conditional access policy blocks it" (53003): your IT administrator's policy is blocking the sign-in. Ask them to allow OmniBrand, then reconnect.
- "the permission for OmniBrand was removed" (65001): a Microsoft 365 administrator removed or never granted consent. They must grant OmniBrand's permission again, then reconnect.
- "the account is not assigned to the OmniBrand app" (50105): your administrator must assign the account to the OmniBrand app in Microsoft Entra, then reconnect.
- "the OmniBrand app registration was refused": this is on our side, not yours. Do not reconnect; write to support.
How to reconnect
- Open Accounts (/app/channels) and click Reconnect on the mailbox.
- Sign in with the Microsoft account that owns the mailbox. For a shared mailbox, sign in with your own account that has access to it: Reconnect carries the shared address, so the shared mailbox's account comes back with its history and your own mailbox is not added instead.
- Check the badge says Connection: OK. New mail is checked every minute.
Good to know
- Shared mailboxes are supported: type the shared address (for example ticketing@yourcompany.com) when you connect email, or change it later under Mailbox to watch on the account.
- Replies go out from the mailbox, threaded under the customer's email, and appear in its Sent Items.