Domain Issue on dedicated server with multiple domains

Dear Gurus,

I m having openfire on my dedicated server with mulitple ips and dns lets say . www.mydomains.com and mydomain.com,

My servers main dns is mydomaini.com (), but where I wnat to use openfre for my other host name, mydomains.com,

I have change the property in openfire xmpp.domain=mydomains.com but unluikly when I m creating new user with using mydomains.com address ,I got user created succuefuly but its using my main dns mydomaini.com

with xiff I cant interacted my users , even I m login but it seems like users have differnnce I m login with user@mydomains.com and want to interact with user2@mydomaini.com

Help Required Please.

thanks in advance