On Sun, 13 Dec 2020 at 18:22, Elise <dovecot_ml@cloudzeeland.nl> wrote:
Op 12-12-20 om 17:20 schreef Elise:

> dovecot-2.3.11.3_1
> Providing the correct email address and password.

I think the origin of this issue is caused by Outlook itself.
Setting up a new account in Outlook, one has to provide an email address
instead of a user name. With using BSD usermanager, adding a user named
'ilse@mydomain.com' is converted automatically to user 'ilse'.

I am not expecting that Microsoft will solve this issue on short term
though. Will stick with Thunderbird (as I already planned) but how nice
it would be to make Outlook my backup mail client with
IMAP/Dovecot/Postfix...

Best, E.

Elise, your problem is simple. 
And yes, I am a *BSD diehard for donkey years.
You want to setup a system that handles virtual users.
The BSD usermanager creates system accounts (/etc/passwd) and those cannot be made to be user@domain by default, although Dovecot authenticating system users and concatenating the domain is possible.
So what you need to focus on is whether you want to authenticate system users or virtual users. Read Postfix docs about this.
For Dovecot, it is easy. Just look at the passdb and userdb configs and Dovecot will do whatever you decide from the above choices. It can actually do both - and many!
I have a system where dovecot authenticates system accounts and vurtual accounts (MySQL and SambaAD) .
I am an Exim user though.


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Best regards,
Odhiambo WASHINGTON,
Nairobi,KE
+254 7 3200 0004/+254 7 2274 3223
"Oh, the cruft.", grep ^[^#] :-)