Forgive me if there is a way to do this, and feel free to respond with a "how to", but I can't find the functionality I am looking for in the docs or forums.

Basically I am looking for mail list functionality using Zoho mail.  This would be used to drive e-mail marketing campaigns ( and thus could be linked with CRM ).  Users could opt-in our out of mailings, and again, new campaigns could be generated using e-mail lists and CRM.  Thoughts, idea's, suggestions?