SquirrelMail for Mail Server on Local Network

This section provides a tutorial example on how to configure a SquirrelMail Webmail site to access a remote mail server on the local network.

If you are configuring SquirrelMail to access a mail server on the local network, you can try to use IMAP on port 143 and SMTP on port 25 without TLS encryption.

This tutorial shows you what I did to configure SquirrelMail for a mail server, 192.168.1.100, on the local network. The mail server is serving 5 protocols on 5 different ports:

1. Replicate the SquirrelMail Webmail site directory.

herong$ cd /var/www/html

herong$ sudo cp -pR mail mailx

2. Update the configuration of the new site to use SMTP on port 25 and IMAP on port 143 that requires no certificates.

herong$ cd mailx
herong$ sudo perl config/conf.pl

General Options > Data Directory: /var/www/html/mailx/data/
General Options > Attachment Directory: /var/www/html/mailx/attach/
Server Settings > IMAP > Server: 192.168.1.100
Server Settings > IMAP > Port: 143
Server Settings > IMAP > Authentication: login
Server Settings > IMAP > Secure IMAP (TLS): false
Server Settings > SMTP > Server: 192.168.1.100
Server Settings > SMTP > Port: 25
Server Settings > SMTP > Authentication: none
Server Settings > SMTP > Secure IMAP (TLS): false

3. Run the test script in a Web browser. The SMTP on port 25 looks ok. But IMAP on port 143 is not usable. The mail server rejects using password in plaintext with no TLS encryption.

herong$ firefox http://localhost/mailx/src/configtest.php

...
Checking outgoing mail service....
  SMTP server OK (220 mail.herong.home ESMTP Postfix)

Checking IMAP service....
  IMAP server ready (* OK [CAPABILITY IMAP4rev1 SASL-IR ...

  ERROR: Your server doesn't allow plaintext logins.
  Try enabling another authentication mechanism like CRAM-MD5, DIGEST-MD5
  or TLS-encryption in the SquirrelMail configuration.

Okay, the mail server is smart to reject remote client connections on IMAP port 143, because the client needs to send password information in plain text over the network. Someone else on the network can sniff network traffic to obtain the password information.

So you should use IMAPS on port 993 with TLS encryption as shown in the next tutorial.

Table of Contents

 About This Book

 Introduction to Linux Systems

 Process Management

 Files and Directories

 Running Apache Web Server (httpd) on Linux Systems

 Running PHP Scripts on Linux Systems

 Running MySQL Database Server on Linux Systems

 Running Python Scripts on Linux Systems

 Conda - Environment and Package Manager

 GCC - C/C++ Compiler

 Graphics Environments on Linux

SquirrelMail - Webmail in PHP

 SquirrelMail Webmail Installation on CentOS

 SquirrelMail Configuration on CentOS

SquirrelMail for Mail Server on Local Network

 SquirrelMail Configuration for IMAPS Port 993

 Provide Self Signed Certificate to SquirrelMail

 SquirrelMail Configuration for SMTPS Port 465

 SquirrelMail Configuration for QQ Mail

 Tools and Utilities

 References

 Full Version in PDF/EPUB