How to enable IMAP?

I want to install SuiteCRM, which requires IMAP for its mail campaigns function.

yum install php-imap indicates that it’s already installed. However, I don’t see anything mentioned of the module in

How do I go about enabling this?

Have a look at Dovecot - is an open source IMAP and POP3 server. However, if Virtualmin was installed with automated install script, then everything should be set up and ready. You would need to have a look at Edit Users section

If it’s not setup and installed, it might be difficult to set it up yourself, (considering that you’re asking about it). SuiteCRM allows using any external mail services, like GMail or Yahoo. I would just registered an extra account with one of them and used their mail server instead.