You need to see which programs are listening on which ports, etc. For that, please run the following command:
and post the results.
If postfix is running (in which case you'll see master listening on port 25), then it may be a postfix setting. Check your postfix's config file settings (usually found in /etc/postfix/main.cf), or post the output from the following command:
which will show us the postfix settings not left at their defaults. Pay close attention to the following settings:
There may be missing postfix files, or files with the wrong permissions set. To check that out, do:
Have your tried running:
The output will be:
postfix/postfix-script: fatal: the Postfix mail system is not running
if postfix wasn't running, in which case you should start it with:
After doing "postfix start", wait about 10 seconds, and then re-run "postfix reload". If it still says postfix isn't running, then postfix is unable to successfully start, and you should check out your mail log file(s).
egrep '(fatal|warning|error)' /var/log/maillog
Note: Your maillog file may be elsewhere.
Keep us posted.