Alternate SMTP Port By admin on March 5, 2009 in Email Here’s a quick IPTables rule to setup an alternate non-standard SMTP port without reconfiguring the mail server software: /sbin/iptables -t nat -A PREROUTING -p tcp -m tcp --dport 2525 \ -j REDIRECT --to-ports 25 12 /sbin/iptables -t nat -A PREROUTING -p tcp -m tcp --dport 2525 \-j REDIRECT --to-ports 25 Related posts: Bind Zimbra On Specific IP Address Relay Control Upgrade RedHat 9 to Sendmail 8.12.11 Postfix + Spam Assassin + ClamAV on RHEL Mailman
