If you were looking for something specific you probably got redirected here from an old link to my (now gone) drupal blog. I migrated all the pages & blog entries to this blog, so just use the search here to find what you were looking for.
So I set up my Univention Corporate Server as Mail server (Dovecot, postfix) .. which worked just fine, but a few things to take note of:
After having some issues with the amount of DB queries / connections I decided to try redis for file locking with nextcloud.
So I had the problem that for some reason I couldn'T send emails anymore ..
So to avoid having to add (more) pinhole NAT or similar I was looking into adding a responce-policy zone to UCS. Looking around for a while I did not find a way to do this with the admin interfaces or ucr.
So I was having a small issue on a server I cannot easily update where certbot was out of date and gave me this error: "Client with the currently selected authenticator does not support any combination of challenges that will satisfy the CA."
Took me a while due to some dependencies my last updates had skipped certbot and it was still quite old .. Digging around a bit I found out that the error I had might be fixed already. But without a good way to update it I was a bit stuck..
Then I remembered .. who said I had to use the system installed certbot.. so virtualenv to the rescue: