Re: How do I make mail authenticate?

Addition:

> Is there a way to find out which parts of the config affect which
> utility?

This is discussed in detail here:

  https://mailutils.org/manual/html_node/configuration.html

  To see which configuration files are being used by a particular utility,
run it as:

  prog --config-lint

To get a detailed trace of each configuration statement used, along
with its location in the configuration file, use

  prog --config-lint --config-verbose

These and other configuration-related options are discussed in
detail in the documentation (see the link above).  
  
Regards,
Sergey