Error: IMAP is not included in your PHP installation, cannot continue

Hi, just wondering if I could get some pointers please? Let me know if I should post this else where.

At the Process Bounces page I receive the error:
Error: IMAP is not included in your PHP installation, cannot continue
Check out http://www.php.net/manual/en/ref.imap.php

PHPinfo(); does not give me the output shown above by @duncanc

php -m does not show the imap module.

php -v
PHP 5.6.37-1+ubuntu14.04.1+deb.sury.org+1 (cli)
Copyright © 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright © 1998-2016 Zend Technologies
with Zend OPcache v7.0.6-dev, Copyright © 1999-2016, by Zend Technologies

I am running Ubuntu 14.04

PHP5.6 and 7.0 are installed.
phpinfo(); says that I am using
Loaded Configuration File /etc/php/5.6/apache2/php.ini

My install procedure was
apt-get install php5-imap
php5enmod imap
service apache2 restart

To
/etc/php/5.6/apache2/php.ini
I added
extension=imap.so

For some reason I still receive the initial error from PHPlist
I am running PHPlist v3.3.6