Hallo Elise,
Wednesday, December 16, 2020, 8:49:54 PM, you wrote
Adding an account in Outlook (2019 in my case) one must provide an email adddress. Example: elise@cloudzeeland.nl So that would be the username (and not simply elise). Dovecot does not understand that and respose with a 'non existing user' kinda of message.
Do agree that MS should be less arragand on this; perhaps a member of MS reads this topic and is willing to help me/us out with this. Imho not only should a webbrowser be cross compatible; a mailclient also should respect global IMAP rules' configuration.
check Christian Schmidts proposal. At the start menu type "Control Panel" and in the opening control panel search for "mail". You will get a new window where you can set e-mail addresses and usernames independently. In your example, the username elise would be possible.
I hope this helps.
Michael