Exchange2K @ Active Directory

Help.....Is there any way to add 2 SMTP email addresses to a user account in Active Directory.
We have merged our retail and whoesale corporate offices and now some users want to be able to use both address ex: kurtg@schurman.com and kurtg@papyrus-sfp.com. When I add the other address in AD it let's me. But then I go test a email it doesn't work. then I check AD again and the smtp address is gone. If anyone has any suggestions let me know.