====== MTA - Mail transfer agents ======

====== Exim ======
small mail transfer agent listening on port 25 - useful on local server
sometimes it crashs.. ^^

===== config =====

setup a correct (dns resolvable) hostname:
  dpkg-reconfigure exim4-config

mailservers may block temporary dyndns IPs or move them to spam!


===== mailq =====

check for frozen messages:
  mailq


remove all frozen messages from mailq:
  exim -bp | exiqgrep -i | xargs exim -Mrm


====== SSMTP ======

not even a daemon. it just forwards mails. very simple and useful for websites and system to just send mail.

/etc/ssmtp/ssmtp.conf:

  # The user that gets all the mails (UID < 1000, usually the admin)
  root=username@gmail.com

  # The mail server (where the mail is sent to), both port 465 or 587 should be acceptable
  # See also https://support.google.com/mail/answer/78799
  mailhub=smtp.gmail.com:587
  
  # The address where the mail appears to come from for user authentication.
  rewriteDomain=gmail.com
  
  # The full hostname
  hostname=localhost
  
  # Use SSL/TLS before starting negotiation
  UseTLS=Yes
  UseSTARTTLS=Yes
  
  # Username/Password
  AuthUser=username
  AuthPass=password
  
  # Email 'From header's can override the default domain?
  FromLineOverride=yes


info copied from: https://wiki.archlinux.org/index.php/SSMTP