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I'm using Thunderbird to access my Office 365 mail account and it has been working fine (a couple of month ago I also switched to OAuth2 due to deprecation of basic IMAP authentication). However, since 2022-11-01, Thunderbird is unable to subscribe to IMAP folders. Last time I know it was working was last Friday 2022-10-28. Thunderbird is able to list to available folders (e.g. when opening the "Subscribe" dialog from the mail account settings), but cannot subscribe to them. I enabled IMAP logging in Thunderbird, and it shows that the server answer the subscribe request with "BAD SUBSCRIBE".
It is not a password/authentication issue, as Thunderbird can still see the content of "Inbox" and "Deleted Items". And if I disable the option "Show only subscribed folders", it can access everything in my Office 265 account.
Edit: here's the relevant logs from Thunderbird (note: I've replaced the actual folder name with "xxxx"):
[Parent ...: IMAP]: I/IMAP ...:outlook.office365.com:A:SendData: 76 subscribe "INBOX/xxxx"
[Parent ...: IMAP]: I/IMAP ...:outlook.office365.com:A:CreateNewLineFromSocket: 76 BAD SUBSCRIBE failed.
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Any news on this ? It's been 2 weeks with this issue and it's getting frustrating...
Great detective work! Thanks. Now there's hope of a MS 'fix'.
I have three accounts as mentioned in my post above. One of the three still works. This working account is used only for testing and has had little use lately. The other two have a lot of activity. So my thought is that whatever algorithm was used to change the two not working was based upon usage and that sooner or later the 'test' account will stop working. I'm not much in tune with MS and got hit by the OAuth2 deadline. One of these accounts stopped working at 3:24 AM Oct. 6, and the other two within the next two days. If my memory is correct the 'test' account worked longer with basic authentication than the two that have a lot of activity. Anyway with so many experiencing this problem I agree that MS must have changed something. Maybe they will change it back or at least let developers such as TB know what has changed and what they need to do differently.
I'm seeing the same issue. Thunderbird is reporting "SUBSCRIBE failed" every time I try to subscribe to any IMAP folder except INBOX.
I'm having the same issue with OAuth2 + IMAP as well. I've tried disabling/re-enabling IMAP on the mailbox and have double checked the app permissions in Azure AD. Hope this gets fixed soon.