sendmail local delivery problems
 

I have a sendmail server setup, and everything seems to be working fine except for a local delivery problem.

When I send an e-mail to someone in another domain with the same alias as one of my users in the local domain, it delivers it to the local domain instead of the outside domain.

Example, I sent a message to "jeff@yyy.com", but because I have a user with the alias "jeff" on my local domain "xxx.com" it delivers it to "jeff@xxx.com". If the local domain doesn't have same alias it goes through fine.

I have no idea.

Thanks in advance,

Jeff