Description of problem:

On a freshly installed Satellite, e-mails don't get delivered out of the box. The default is to use sendmail/postfix but the postfix service isn't enabled and running.

We have this documentation about different mail configurations but it doesn't mention the defaults don't work out of the box: https://docs.theforeman.org/nightly/Installing_Server/index-satellite.html#Configuring_Server_for_Outgoing_Emails_satellite

We also have this related bug fix of which shows how to debug the issue but doesn't prevent it from occuring in the first place: https://issues.redhat.com/browse/SAT-27822

I think the service should be enabled by default. If not, it should be documented in the installation guide as part of setup.

How reproducible:

Deterministic

Is this issue a regression from an earlier version:

Probably no but not tested

Steps to Reproduce:

1. Have a freshly installed Satellite

2. Trigger anything that should send a mail, e.g. Administer -> Users -> <user> -> Email Preferences -> Test email

3. 

# mailq
postqueue: warning: Mail system is down -- accessing queue directly 

Actual behavior: postfix stopped, mail not delivered

Expected behavior: postfix running by default or its setup documented in installation guide