Domain Alias w/ UNique Email Account

[fishpop]

I have a domain name, domain2.com, that I want to resolve to the same web hosting directory that domain1.com is using. This can normally be done using a domain alias within Plesk, but I need the email address for address1@domain2.com to be a different account than address1@domain1.com (which Plesk's domain aliasing doesn't seem to support). I think it might be possible by manually adjusting the DNS settings and/or zone file, but I'm no expert and don't know how. Anyone have any guidance?