Mailbox Count

Once per year, we ask that you update the number of declared mailboxes. When it's your time, Cumulus will automatically notify you by email and will even change the Welcome message.

This article applies to Administrator accounts.

How do I do my mailbox update?


Start by logging in to Cumulus and click the Mbx Update tab.


Add a number to the Decl. nb mbx field. This is the new number that will be used to bill you. You can compare this against last year's number (Old nb mbx).


Click the Submit button.


That's it!

Common Questions

What's the difference between Standard Domains and Mirror Domains?

Check out our detailed explanation of the difference in our Managing Filtered Domains article.

What happens if I don't update my mailbox count?

For direct customers, the number of mailboxes will be automatically increased by 10% by the system. For partners, a non-refundable administrative fees of $25 will be charged as well as a temporary adjustment worth 10% of the billing of clients with delayed updates. Once the updates are complete, the difference between the charged temporary adjustment and the new invoice will be billed or credited.

How do I fix the number if I made a mistake? 

You will need to contact our billing department by email so that they can update the declared number of mailboxes. 

How can I update my number of mailboxes if it's not my update period?

This can only be done by our billing department. Write us an email and we can update the declared number of mailboxes for you.

What do all the columns in Mbx Update mean?

Corporate name
Your account name
Domain name
The domain name being updated
Due date
Date by which the update should be completed
Last update
Date of the previous mailbox update
Old nb mbx
Previous number of declared mailboxes
Decl. nb mbx
The number of mailboxes you are currently declaring