Ahhhh ok. Couple more questions on it, and could you clarify if I'm thinking right...

1. If someone has a pop account with an isp, and they want to check their account, they can log in using "my" webmail service and check their account. ie. When they log in it essentially checks their mailbox at the isp and just uses that as their mailbox etc.

2. In this case, would the user need to have an account on any of my domains, or is it seperate of this?

3. Would I need to list the isp domain in my list of domains?

Still not 100% on how/when you'd use it!

Thanks,
R.