SMTP Troubleshooting

Simple Mail Transfer Protocol

• Is the server running?
  • ps aux | grep exim
  • sudo service exim4 status
  • sudo service exim4 start
• Is the server listening on public ip?
  • netstat -atu | grep smtp
• Are there errors in log files?
  • Check /var/log/exim4 directory

Simple Mail Transfer Protocol Debugging

• Send/Receive messages from/to many different accounts.
• Use dig to check if DNS is correct
  • dig @ns1.thegummibear.com thegummibear.com MX

not getting correct reply-to address

• Make sure that /etc/hosts has the fqdn of your mailserver in it. Also, make sure that the same line has a reference to whatever you put in /etc/hostname. Mine looks like this:

  144.38.199.52   mail.thegummibear.com mail-thegummibear
  

Because my hostname (in /etc/hostname) was mail-thegummibear

Last Updated 05/08/2023