I cannot send and/or receive emails.
Please check if Sendmail/Postfix and your POP3 daemon are running by executing
netstat -tap
You will get a list of all services listening on your server.
If they are running re-configure your firewall (iptables or ipchains) so that the ports 25 (Sendmail/Postfix) and 110 (POP3) are not blocked. If this does not help please check that Sendmail/Postfix is really running on port 25 and your POP3 daemon on port 110.
(Hint for standard RedHat installations: If you have webmin installed and are running Sendmail, go to Webmin->Servers->Sendmail->Sendmail Options. Under SMTP Port Options you often find the following entry:
RH: Port=smtp, Addr=127.0.0.1, Name=MTA
Please change it to Default and then click on Save and Apply.)
About Till Brehm
Over 20 years experience as Software Developer and Linux System Administrator. Till Brehm is the founder and lead developer of the ISPConfig Hosting Control Panel software (since 2000) and he founded HowtoForge in 2005 as a place to share Linux knowledge with other Linux enthusiasts.
