[Exim] rewriting domain and adding X-header

Hi,
I'm currently trying to rewrite user@dom1 to user@dom2
however, i wish to use *@dom1 to *@dom2
If this is successfull, i wish to insert an X-header to tell the user in his
outlook client that he needs to inform the user of his change in email addy.

Any ideas ?

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Thank-you for your time.

John Ward