The imap extension of PHP helps you to work with the IMAP protocol, also with work with NNTP, POP3 and local mailbox access methods.

Install php5-imap

Following command will help you to install on Ubuntu.

sudo apt-get install php5-imap


After installed, enable php5-imap

sudo php5enmod imap


Last thing is RESTART

sudo service apache2 restart


Do you want to verify?

php -m|grep imap


Create a file in web directory name it info.php

vi info.php 


nano info.php

Paste below given code in info.php



To verify?

Open your site with /info.php

For example: