i followed a this tutorial for relay external ..... and now my mail is not delivered to yahoo but works with gmail and hotmail.

How do i reverse the changes i just made?

Some mailservers require to use their smtp server.

Set first in the admin console the smtp server: Servers > MTA > Relay MTA

For this setup, edit the postfix.cf file:


change the relayhost directive


     For Shaw customers, change the DS line to read:
     relayhost = shawmail.cg.shawcable.net

     For Telus customers, change the DS line to read:
     relayhost = mail.telus.net

If you need to login with your mail account:

echo mailrelay.example.com user:password > /opt/zimbra/conf/relay_password

   1. Generate the Password database from the file 

postmap /opt/zimbra/conf/relay_password

   1. Test that the correct username/password pair is returned when calling the script 

postmap -q mailrelay.example.com /opt/zimbra/conf/relay_password

postconf -e smtp_sasl_password_maps=hash:/opt/zimbra/conf/relay_password

postfix reload