http://www.google.com/support/a/bin/answer.py?answer=67359&topic=14867
Symptom: Email addresses are rewritten as user@ghs.google.com instead of user@your_domain.com.
The intent of the blog is to capture solutions for some of the common questions posted on the Google Apps forum. Answers are based upon the experience of techlover and other Power Posters on the GApps forum as well as Help pages supplied by GApps.
http://www.google.com/support/a/bin/answer.py?answer=67359&topic=14867
Symptom: Email addresses are rewritten as user@ghs.google.com instead of user@your_domain.com.