Setting up external user to send email

Want to setup an account so it shows up in address book to send email to outside address. What I have done thus far is:

Non-GroupWise domain, post office and user

I configued this using the instructions in Novell docs:

Novell Doc: GroupWise 8 Administration Guide - Adding External Users to the GroupWise Address Book

What I want to know now is what else needs to be done to user so it knows where to send the mail. Do I need to setup internet addressing on the account as well.The docs really don't go into that part. Basically what we want to do is setup an internal distribution list to have an internal account plus this external one so the when the original email arrives to the list, it goes to both accounts. Any help would be appreciated.