HTTPS://FIRST2HOST.CO.UK/BLOG/INSTALL-EXIM-EMAIL-AND-DOVECOT-ON-UBUNTU-AND-DEBIAN-SERVERS/ FUNDAMENTALS EXPLAINED

Be certain that the ip tackle of your MX (mail server) is of that server on which you will setup postfix and dovecot.If this will work you know the firewall is not the difficulty. So we can easily dig deeper. Install tcptraceroute and trace the route to a mail server or even the just one Using the relationship timed out error.As well as 1Ka6u5-0003