Thunderbird IMAP responded: User is authenticated but not connected

Could you ask him Eric to stop hijacking this thread?

Could you ask him Eric to stop hijacking this thread?

Short answer - if the copying of sent mail issue Eric had proves to be nothing to do with the IPv6 fault, AND there is anything of significance to still be done on the former, we can start a separate thread - if those posts are causing anyone a load of grief.

Longer answer - Eric and another of his countrymen had the same IPv6 issue as the rest of us, but were using Thunderbird in German language mode, and just needed help on where/how to make the change. It then transpired Eric had a secondary issue which was an error relating to the failure to save a copy of sent messages - and that was hopefully resolved this morning.

Three possibilities spring to mind:

1. If the sent message issue occurred around the IPv6 fault/workaround, I wouldn't consider that hijacking the thread as the two could potentially be linked in some obscure way. That's why I started posting replies in English in case anyone else has the same secondary issue.
2. Eric could have been experiencing BOTH the IPv6, and the IMAP Subscription fault which is still open from November and can result in the exact same problem saving sent messages prior to doing the workaround for that. I've not seen any evidence that this is the case for Eric, but I have had both faults on my tenant, as has koffi2k and probably many others.
3. The problem saving sent mail might be an entirely separate fault - which is why I asked for timings in my earlier post to try and understand if that is the case.

Worth considering that Thunderbird users accessing O365 services are going to be predominantly non-corporate - so we're likely to have had end users from right across Europe being hit by this and having to try and fathom it out for themselves, in whatever language they happen to speak, and likely without a clue what IPv4/IPv6 even is. That's a very big ask of end-users when as an SA myself, even I don't know what the hell Microsoft have done to cause the IPv6 and Subscription faults, such is the potential depth, complexity, and obscurity of both.

Back to the IPv6 issue, the latest update I have from Microsoft on my ticket is from this morning "We are checking with our escalation team for further plan of action". I still haven't been able to make contact with any of my affected users to do further testing - so has anyone out there backed the IPv4 workaround out, and found they still have the fault?

Thanks.

Could you ask him Eric to stop hijacking this thread?

Short answer - if the copying of sent mail issue Eric had proves to be nothing to do with the IPv6 fault, AND there is anything of significance to still be done on the former, we can start a separate thread - if those posts are causing anyone a load of grief.

Unfortunately, it has made it harder to find the posts at the end of this thread where people are reporting that the issue seems to have been silently resolved by Microsoft. I’m convinced that his issue is not the one reported in this thread. However, I cannot prove that.

This forum itself doesn’t support threading. If you and Ian could create a new post and collaborate there, that would work better with how this forum works.

Back to the IPv6 issue, the latest update I have from Microsoft on my ticket is from this morning "We are checking with our escalation team for further plan of action". I still haven't been able to make contact with any of my affected users to do further testing - so has anyone out there backed the IPv4 workaround out, and found they still have the fault?

All I can say is that I stopped using the workaround since the moment I reported I no longer needed it and that I have not had an issue since then. I have yet to see a counter-report here, so I am convinced that means that this particular incident was resolved globally and has not (yet) recurred.