Don't set default mail user/password

[johanvdw]

It should be possible to connect to a mail server without username and password (on localhost/local network).

This is part of the template, but because these variables are set as default they will always be included

[rixx]

Hmm, does this still render cleanly when the variable isn't set? I have vague memories of having to do is_defined or |defined or somesuch in Ansible when variables were not guaranteed to be present.

Maybe better to set them to a null value, to make it clear that they exist, and then check if they are empty? AIUI, defaults/main.yml serves as a common entry point for people looking for variable documentation, and removing them entirely makes them hard to discover.

[johanvdw]

I had another look at the code and setting them to None or False should indeed work.

[rixx]

Sounds good! ping me when you've updated the PR and I'll merge it :)

[rixx]

Thanks!