Why can't I send mails to AOL?

Some people reported to have problems sending mails to people at AOL. AOL has a spamfilter on port 25 blocking all requests to send mail over that port. So we've to change a view settings in postfix to let him try to send over port 587. Please open /etc/postfix/master.cf and comment out the following line:

submission inet n - - - - smtpd

Now run

 
 # /etc/init.d/postfix reload
 

Done!

Test it from another host or a windows box via telnet.

 
 # telnet your-server.tld 25
 

Quit with simply typing quit if connected.

 
 # telnet your-server.tld 587
 

If you can connect to both ports all went fine.