Return Path is being rewritten

[wolfee at earthlink.net]

Hi,

I am not sure if this is a MailScanner or Sendmail thing but hopefully you
guys can point me in the right direction.

I have a client who just got a new email address and when he sends email to
me the return path is rewritten to user at webhostingcompany instead of
user at domainname. To make things more interesting his webhosting provider and
email provider are different companies. If I send email to a email address
that is not being scanned by MailScanner the return address is correct. We
scan about 30000 emails a day and I have never seen anything like this. Any
suggestions?

Thanks

Matt

P.S. Sorry if this is a repost; I didn't see it come through the first time.