I can see also that we can’t change the port of pop(s) imap(s) services, it is written in the stone of templates, there is some reasons for that ?
What is the most awesome module/feature for NethServer, that does not yet exist?
We made this kind of choice to simplify the configuration.
But let me reverse you question: is there a reason to change standard pop(s) and imap(s) ports?
A really short answer : yes
Since thunderbird allows you to decide which port can be used then non standard port exists
You can use an really ugly hack to achieve this: create a port forward from the non standard port to the standard one.
I know, it’s really naive
I have seen yesterday a question about how to change the port of openvpn, probably the same question will be an issue here.
IMHO every service should have its port changed if needed, it is the first advice concerning security matter.
That’s true @giacomo but with port forwarding you have to remember/manage (choose what you prefer) an additional external configuration, I mean: it is an indirect configuration.
If I can change directly ssh port this should be possible for every service IMHO.