The timescale for emerSMTP is a little hazy right now, unfortunately. I've just had a look at where I'd got up to with it (I haven't had a chance to look at it for months), and the POP and SMTP functionality is there, and it runs natively as a service, but there is still a fair bit to do. I may release a beta fairly shortly after I get back to it.
At the moment I am developing the next version of Rules Manager (as well as being involved in several web projects), so time to get back to emerSMTP is still a fair way off. Hopefully this year though!