Here are the steps to create a new user in Smarter Mail 9 Enterprise. 
Add New Email Address
1. Log into the webmail interface. webmail.domain.com as a mail administrator.
2. After Login, select the Settings Icon from the left hand menu.
3. Expand Domain Settings and Select Users.
4. From the Main Window, select New.
5. Fill in new user details with the following format.
User Name: firstname.lastname
Pass: secure password
Display Name: FirstName LastName
Reply-To Email Address: firstname.lastname@domain.com
Backup Email Address: Optional (Use Existing personal address of user if filled in)
User Status: Enabled
Mailbox Size Limit: 50 MB
Enable Outgoing Mail Signing: Enabled
6. Click Save when complete.