Thanks Everybody I configured the relayhost entry in main.cf in /etc/postfix path as relayhost = [my service provider relay host] Thats all, I am able to send / recv email. Next how do I make sure, my spam/antivirus filtering is working properly.... Is it that only maillog i cam check, or is there any effective way of checking it. Thanks -Austin On Fri, Mar 15, 2013 at 11:13 AM, Austin Einter <austin.einter at gmail.com>wrote: > Thanks John > By the way I checked with my service provider. Their ISP does not block > 25. But to successfully deliver SMTP mail, I need to use their relay server > (it uses port 25 only). > > Where will I configure their relay server . Is it in /etc/postfix/main.cfor any other file. Do I need to modify anyting in dovecot or amavisd > configuration??? > > Thanks > Austin > > > > On Fri, Mar 15, 2013 at 9:55 AM, John R Pierce <pierce at hogranch.com>wrote: > >> On 3/14/2013 9:20 PM, Les Mikesell wrote: >> > Some ISP's block port 25 if it is a 'home' type connection. Comcast >> > recently started blocking and I can't connect there from home either. >> >> >> configure your mail server to use your ISP's mail server as a >> 'smarthost', OR configure it to use an external (coloc or whatever) >> server as smarthost via port 587 with authentication. >> >> >> >> >> -- >> john r pierce 37N 122W >> somewhere on the middle of the left coast >> >> _______________________________________________ >> CentOS mailing list >> CentOS at centos.org >> http://lists.centos.org/mailman/listinfo/centos >> > >