If you are setting up your email for the first time, you can have a look at some of the email video tutorials we have set up; the settings however, are unique to each domain.
imap.domain.com pop3.domain.com smtp.domain.com
If you use Sonassi Hosting for DNS control then all the A records will be automatically created, if not, then you must set CNAME records to suit the below:
imap.domain.com:sms-guile.sonassi.com pop3.domain.com:sms-guile.sonassi.com smtp.domain.com:sms-bison.sonassi.com