Releasing mailboxes
How to release an unused mailbox (only applies to paid and not free or purged mailboxes)
When you buy a mailbox (Standard or Premium), you're actually buying a “slot” to which you assign an email address when you create a mailbox.
If you have unused free slots, release them and you'll be automatically refunded on a pro rated basis to the prepaid account.
To do this, go to the Domain name / Email menu.
In the Email section, click on “Release unused”.
Note: If the button is missing or grayed out, you don't have any slots to release.
On the next page, select the number of Standard and/or Premium (free) slots, then click on “Release”.
The amount will be calculated automatically, and the refund will be credited to the prepaid account to which it applies.