Hopefully an easy header rewriting problem for Postfix

[Clint Olsen]

I essentially want to rewrite all envelope senders of the form:

@host.my.domain

to just

@my.domain

The examples in the Postfix docs seem to make it seem like the patterns
only allow you to specify explicit recipients at the end of a rewriting
rule, but that's not what I want.  I know this was a common thing to do in
Sendmail using that hideous CF syntax.

Any cluepons would be very much appreciated.

Thanks,

-Clint