[exim] Android Outlook App

Hello List,

we have a problem with this app. A customer loves M$. So he tries to
connect to exim as outgoing connection. The IMAP part ist ok, there is
dovecot.

All error messages from the app are wrong, if you give wrong passwords
it gave wrong certificate, correct data gives wrong password and so on...

In the exim log you can see:
2020-12-04 11:36:21 SMTP protocol synchronization error (input sent
without waiting for greeting): rejected connection from xxx I=[xxx]:25
input="\026\003\001"

I think it tries SSL/TLS and it doesn't matter what port you give in the
configuration of the app 25, 587 or 465, all the same. And there ist no
option to tell the app what to use, plain, starttls or ssl.

So my question is, has anyone a working exim config which works with
this very nice app?

As authenticators I have PLAIN, LOGIN and CRAM-MD5 which work with
nearly all other apps, desktop outlook, thunderbird, samsung mail app,
gmail and so on. Port 465 is new at the server. Is there a special acl
missing? I have set tls_on_connect_ports = 465 and exim is listening on
that port. Thunderbird works here too.

Every hint is really welcome.

have a nice weekend
Andreas