Office365 append pending forever

[Kludex]

Hi there! 👋

I need help, but I'll probably be vague, and I know this is probably not the best place to ask this. I'm already using the package, so I'll give it a try here. 😅

I'm having an issue when appending a message on the outlook.office365.com IMAP server. What happened is that it basically keeps on the appending command for a long time (I've removed the timeout, to see if it was just taking too long, but it doesn't finish).

The snippet I'm using is the following:

await imap_client.store(uid, "+FLAGS", "(\\Deleted)")
await imap_client.expunge()
await imap_client.append(message.as_bytes())

I'm trying to modify a body of a message, so I need to get the message, modify it, remove it from the server and add a new one. The log of the first two commands above are fine:

Response(result='OK', lines=[b'4 FETCH (FLAGS (\\Deleted \\Recent))', b'STORE completed.'])
Response(result='OK', lines=[b'4 EXPUNGE', b'EXPUNGE completed.'])

But again, the append keeps forever. 😓

I hope someone can help me out. :)
Thanks for the package!