Der. This is from the Knowledge Base. And it refers to the welcome letter.
"The information that you need in order to set up email accounts for your site is contained within the MonsterCommerce Welcome Letter. To access your default Admin mailbox, and to create other email addresses, go to
http://YourIPAddress:8383. Log in with the username admin@yourdomain.com and the password provided within your Welcome Letter. Once you are logged into the Admin account, chose User Administration under the Administrative Account Options to create new email accounts for your site. If you need us to resend your Welcome Letter, please contact our sales department and we will be happy to forward that information again."