UCS Mailserver with OX doesnt work

I am currently testing the following installation, unfortunately sending email / receiving email does not work.
UCS 5.01, connected to Active Directory of Windows AD
-on UCS package Email installed
-on UCS OX App Suite installed
Users are taken from AD, primary email address is entered
User activated for OX App Suite
UCS set up as mail relay (smtp.strato.de:587)
DNS MX entry set up, firewall allows port 25 through to UCS
Login of users in OX App possible, sent emails in OX App in folder sent => but do not arrive at the recipient (also not spam)
Sent emails to Email User on UCS do not end up in user’s inbox - no idea where they arrive?
No idea anymore…

email is not just port 25, it depends on TLS /ssl ports as well.


solved the problem - problem was the setting of TLS level “must” switched to “may” and now its working!