I have a user that has a primary email on the exchangeserver set to user@subdomain1.domain.com And then the user has a secondary smtp address called user@subdomain2.domian.com When user sends from outside of the exchange organistion the address is correct and can be filtered by the exchange filter rules. But when someone sends an email to user@subdomain2.domain.com within the organisation Outlook translates the address to the primary address. Is there someway to prevent that form happening. The user wants to filter email based on the address. I guess I could hide the user from the GAL but that doesnt seems like a good idea. The system: Exchange 2007 server

This is normal behaviour for Exchange. As far as I know there's no way to suppress it.The only workaround I can come up with is to give that second email address to a DL that has that user as the only member.

Hi,Please understand that Outlook's nickname cache which stores the LegacyExchangeDN as X500 address to send the email within the organization instead of the SMTP email address.Thus, the Exchange filter rules doen't work on this issue.ThanksAllen

Whether you will accept it as an answer or not, there is no way to prevent Exchange from doing that.

You could also write your own transport agent that does this lookup then sets a category on the message. Then you can configure Outlook to filter on the category.