If you want to create a webmail  with your domain, you can use SquirrelMail. SquirrelMail is an open source webmail.

Then how SquirrelMail settings.
Download SquirrelMail  from their official website

http://squirrelmail.org/download.php

Upload and Extract files squirrelmail in hosting (cpanel) your web. You will find squirrellmail   folder, you can rename the folder.In this example, I replace it with a folder “mail“.

This is important because it will relate, you will access the webmail page:  example -> your domain.com/mail

Create a folder on your hosting , give name “Attach”

Open your webmail page,  in this example: ebookengineer.com/mail

(/ mail = because  squirrel mail folder, I replace it with the name “mail”)

Before you can use, you must do the test.
example test :

http://ebookengineer.com/mail/src/configtest.php

Replace ebookengineer.com  with your domain name.

If no errors, you can   use your webmail. but if there is an error, you can   settings below.

Open the config.php file in the hosting = file is located in the  folder config > config_default.php
Edit the file config_default.php after finish, then save the file and rename it to config.php.

Parts that need to be edited:
$domain = ‘example.com’; replace with $domain = ‘your domain’;
example: $domain = ‘ebookengineer.com’;

$smtpServerAddress = ‘localhost’; replace with $smtpServerAddress = ‘domain name’;
Example: $smtpServerAddress = ‘ebookengineer.com’;

Find $data_dir = ‘/var/local/squirrelmail/data/’;   replace with

$data_dir = ‘/home/seswet/public_html/mail/data/’;
Seswet = an account of my cpanel, so you replace with your cpanel user.
$attachment_dir =
Make:
$attachment_dir = ‘/home/seswet/public_html/mail/attach/’;

Seswet = an account of my cpanel, so you replace with your cpanel user.
Then save.

Then do the test once again  http://your domain.com/mail/src/configtest.php

if there is no error, you can login in to your webmail.

Some of Problem :

If you change $smtpServerAddress = ‘localhost’;  to $smtpServerAddress = ‘your domain’;

but after you replace, in case of error and can not send email:

solution: Stick with the $smtpServerAddress = ‘localhost’;

There is error like this,  When you do test and there is error like this:

Warning: fsockopen() [function.fsockopen]: unable to connect to lkps.or.id:25 (Connection refused) in /home/lkpsorid/public_html/mail/src/configtest.php on line 386

    ERROR: Error connecting to SMTP server “lkps.or.id:25″.Server error: (111) Connection refused

Solution :  use this -> $smtpServerAddress = ‘localhost’; 

if you have questions, please comment. If I can, I shall answer.