I would like to know if an alternative to cpop like courrier could be used with cpanel ?

If not, if i'm just configuring my init to start courrier pop, pop-ssl, imapd, and imapd-ssl will have it to work correctly ?
I mean, there's no big configuration and work to do with a pop and imap server... I do not really need an integration into cpanel or whm.

Is it possible ?

ALso, another question. Does exim use standard ssl certs ? I mean, if a buy a starter ssl cert, will it work correctly with exim ? Does email clients accept starter ssl certs ?

Thanks for your help