I am embarrassed about how many questions I am asking just now, but I am very new here.
The imap server seems to have stopped responding to me in the last few minutes.
I am using offlineimap which is known to have occasional synchronisation problems and can (rarely) deadlock.
I had what I thought were such problems a couple of times, and aborted the connection. This is something that I do routinely with several imap servers with no problems.
But now multiple attempts over the last 15 minutes or so have failed. I can still login via Rainloop. Is it possible that my initial broken attempts to connect to the the IMAP server have triggered some protection mechanism? (But see update below).
It could actually be that known bug somewhere in offlineIMAP I guess.
UPDATE: I have just checked again, and it is now working. So perhaps it was offlineIMAP after all, I decided to post this anyway since I know that others here are using offlineimap in case it is useful.