I've got a user (A) who needs to send mail on behalf of someone else (B), but she wants bounces to return to her (A). So I had her test by setting the From field in Outlook and sending me a message.

Result was Return-Path: <B>

Not good.

So I tried it using Personas in ZWC, and the Return-Path was set to <A>. Great.

Now I try to reproduce the issue on another machine's Outlook, and it's behaving in the desired fashion. Both setups have the same version of Outlook, both using ZCO 6.0.6, both running XP.

Any ideas why this might be happening?