Scenario: I am having an issue with exchange when trying to auto send an email from a sun machine to an external email address (vendor). the email is send as web@xxxxxxxxxxx <mailto:web@xxxxxxxxxxx The recipient is doing a lookup to verify the host/domain (an internal machine), and sends a bounce-back because it cannot resolve the host/domain. The sendmail header on the UNIX server is configured to show the recipient this: user@xxxxxxxxxxxx I tried to masquerade the From header to this: user@domain. It did not work. It was working before just fine. Does anyone has any input on this? Thanks Juan