Duplicate e-mails from webmail

I have a user who uses webmail only. The problem is that for some reason every message they send to anyone sends two copies. Any ideas as to why this is happening? If I try sending e-mails through that persons database on a notes admin client only one e-mail gets sent.

Thanks in advance,

Andrew

Subject: Did you try replacing their profile doc?

Subject: how do you do that?

How do you replace the profile doc?