AUTHORIZATIONFAILED — AUTHORIZATIONFAILED

IMAP reported that the authentication succeeded but the user is not allowed to act as the requested identity. This can happen if an IMAP login includes a separate authorization identity that isn't permitted. In practice, with Riposte you usually authenticate as the user themselves, so this error is rare. If encountered, ensure you're logging in with the correct user credentials and not trying to proxy to another account. No special API call will fix it; the credentials used must be authorized for that mailbox.