For Plesk 5.x (MDH and Upipe hosting accounts):
- Log into your Plesk control panel.
- Click on the desired domain.
- Click on the Mail button.
- Type in the name of the desired mail user.
- Click on the Add button.
- Check the box next to Mailbox.
- Enter a password for the new user in both password text boxes.
- Scroll to the bottom of the screen and click on the Update button.
For Plesk 7.x (OHP and WebPro)
- Log into your Plesk control panel.
- Click on the desired domain.
- Click on the Mail button.
- Click on Add New Mail Name.
- Type in the name of the desired mail user.
- Enter a password for the new user in both password text boxes.
- Check the box next to Mailbox.
- Enter the size you wish the mailbox to be.
- Click on the OK button to save your changes.