[cisco-voip] Unity mail domain

[Robert]

Greetings!

I think I know the answer to this, but thought I might ask here before I
chase it too far.

Our Unity sits in it's domain all by itself. There is no other Windows
domain here, nor is there likely to be one. When a user's mailbox sends
an email notification, which as historically worked, the message appears
to be from userid at morrisonccm.com, which is not really a valid domain
name. Our provider's new Barracuda firewall and email filter rejects
these messages as being from an invalid domain. Yes, they can whitelist
the domain name and force them through, but they would prefer that the
emails come from a valid domain name.

So, here's the question. Can that email "from" domain name be changed
without changing the windows domain Unity was built on?

Thanks!

Robert