Cartika new enterprise email service allows customers to create exchange users, and regular pop/imap users, on a single domain. no complicated mail forwarding, aliasing, etc. its completely integrated and plug and play. Customers pay 1 rate for regular pop/imap users and then a full rate for exchange users.
The process is extremely straight forward. Once you have signed up for the service, and created your organization, added your domains, etc. you simply then create a new email user and select exchange or pop/imap during the creation process. the rest all happens automatically for you
under mailboxes section, select "new mailbox"
Create the mailbox as per normal, and in the "mailbox plan name" section, simply select full exchange or pop/imap. whichever you select is what will be created and what you will be billed for.