Free Linux Tutorials

Relaying to Gmail via smtp.gmail.com can be accomplished by configuring your Postfix with SASL authentication and TLS encryption.

The common errors you will encounter if sending from your postfix mail server failing to gmail.com domain but works in other domains are:

@/var/log/maillog
-Must issue a STARTTLS command first
-certificate verification failed for gmail.com:unable to get local issuer certificate
-Authentication Required. Learn more at 530 5.5.1 http://mail.google.com/support/bin/answer.py?

How to fix?

Assuming you already installed Postfix and everything works fine except sending to gmail smtps, here are the steps to follow:

1. Configure Postfix main configuration

For those who uses java server pages via Tomcat server on Linux, providing secure transaction on your website thru SSL protocol is a must.  By this of course  we need to install a CA assigned certificate on the server.

The procedure below is a sample installation of  SSL certificate which tested working on my site .

Prerequisites:

Linux (tested on CentOS 4.3 x64 and later)
OpenSSL
JDK 1.5 ( J2SE 1.5.09 at the time of this writing)
Tomcat server (Apache Tomcat 5.5.20 binary version for linux)

SETUP

1.    Linux
It is assumed that CentOS is ready and updated before installation of other packages.