The other account is fine at the moment. I've been using TB for some 20 years now with no issues, and of course nothing has changed at my side (apart from recent TB updates but I don't think there has been one for a couple of weeks) so I suspect this is some sort of a change made by Hotmail/Outlook.An error occurred while sending mail. The mail server responded: 5.3.4 554 5.2.0 STOREDRV.Submission.Exception:SendAsDeniedException.MapiExceptionSendAsDenied; Failed to process message due to a permanent exception with message Cannot submit message.
Googling brings up reference to something called 'Clutter' which I have never heard of so I suspect it's a new thing that Hotmail are rolling out. There is nothing in my Options about it and so again I suspect they are rolling it out or something ... (I can't find the article I saw now ... silly google!)
I'll try sending from time to time and see if this just goes away ...
Anyone else encountering this? Does anyone know what the solution is?
Setup details: I have two Hotmail accounts with different logins. A standard Thunderbird install on a Windows 10 PC. The two accounts are represented in Thunderbird, and I use TB for all email handling etc. As far as I know there's nothing fancy or customised about the install or usage.
I tried compacting the TB folders ete just in case but it made no difference.