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

1. Wonder why you can’t send email from your linux server?

2. Is your mail server or 3rd party email hosting provider requires authentication for your outgoing server to send out emails successfully?

3. Are you using a default sendmail email client on your linux box and wonder why your getting maillog errors such as this:

——-sample sendmail maillog error from my nagios server—————
Oct  2 17:03:54 nms sendmail[25657]: n9293qiw025655: to=<nagios@freelinuxtutorials.com>,

ctladdr=<root@nms.freelinuxtutorials.com> (0/0), dela0928, relay=smtp.freelinuxtutorials.com.

[216.200.145.17], dsn=5.1.1, stat=User unknown
Oct  2 17:03:54 nms sendmail[25657]: n9293qiw025655: n9293siw025657: DSN: User unknown
Oct  2 17:03:54 nms sendmail[25657]: n9293siw025657: to=<root@nms.freelinuxtutorials.com>,

I.    Introduction

This document will discuss installation and configurations how-to on setting up POP3 using Dovecot (www.dovecot.org), SMTP using Sendmail (www.sendmail.org), Email Security System using MailScanner (www.mailscanner.info)  and a Web-based front-end to MailScanner using Mailwatch (mailwatch.sourceforge.net)

II.    Planning the Installation

System Requirements:

a.    Linux Operating System (Kernel 2.2 and later)
b.    Apache Web Server
c.    Perl and perl modules
d.    GCC
e.    MySQL
f.    Vi editor
g.    PHP (w/ MySQL & GD Support)
h.    DBD
i.    DBD-MySQL
j.    wget
k.    unzip/unrar
l.    Dovecot
m.    Sendmail
n.    MailScanner/ClamAV/SpamAssassin
o.    Mailwatch

MailWatch for MailScanner is a web-based front-end to MailScanner and features include displays of inbound/outbound mail queue size, load Average and today’s totals for messages, spam, viruses and blocked content on each page header, Quarantine management allows you to release, delete or run sa-learn across any quarantined messages etc.

Tested on CentOS 4.4, MailScanner ver. 4.57.6, Sendmail-8.13

Requirements:

a.    Working MailScanner setup
b.    MySQL
c.    Apache
d.    PHP (w/ MySQL and GD Support)
e.    Perl
f.    DBD
g.    DBD-MySQL

QMAIL HOW TO

I.    Qmail Installation

A.    INSTALLATION

A.1. Software Pre-requisites
1. Linux Operating System
2.Apache Web Server
3.Perl –any version  of 5
4.GCC – the gcc compiler
5. wget – use for downloading installers
6. patch & patchutils -

Access to a domain name server (DNS) is highly recommended.

A.2  Download the source