Hello, I use 12 mailboxes with Thunderbird. Four of them are Microsoft 365 mailboxes configured with IMAP and SMTP (with OAuth2). All of these 4 Microsoft 365 mailboxes end up in error randomly for about 25% of sync operations (Such as Retrieve e-mails, save a draft on the server), as shown on the enclosed screenshot. These Microsoft mailboxes work very well "most" of the time though, and sometimes require to click the "Retry" button 1 or 2 times in a row before the sync operation actually succeeds. This makes the e-mailing experience with Microsoft 365 very tiring. All other non-Microsoft accounts never fail this often and when they do it is for a good reason (Internet disconnected or server status down). I suspect Microsoft to reduce QoS for all non-MAPI clients (or maybe even all non-Outlook clients). Can this be a reality? And what can be done on the Thunderbird side? Can we make the sync failure silent unless 3 or 4 fail in a row? (I know that using a MAPI extension for Thunderbird is an option but I'd prefer not too).