SOLVED Quota Limits for Email?

Carlos Mendoza

Oct 26, 2018
El Salvador
cPanel Access Level
Root Administrator

I am thinking of acquiring a server with a license from CPanel with a supplier, but I always find information about the limitations with the quota of the mail accounts.

I have seen issues that speak that does not support emails greater than 2Gb, in other 1Gb; but I have seen some that speak of accounts with mailboxes of up to 18Gb in some threads.

If I have my own server with WHM / CPanel installed can it support mail accounts with a large tray space or is it limited?

I think this topic has been discussed before, but I've searched threads, and there are different answers.


Get Proactive!
Apr 8, 2003
Chesapeake, VA
cPanel Access Level
DataCenter Provider
Exim doesn't even really handle the mailboxes, that's dovecot, but I have seen mailboxes with 50 GB of mail in them, though I don't generally suggest that.
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Staff member
Apr 11, 2011
Hello @Carlos Mendoza,

We also document the quota limits on our Email Accounts document:

Mailbox Quota
The quota for an email account defines the amount of mail that the account can store. When the account exceeds this limit, the system returns any incoming mail to the sender with a message that states that the recipient’s mailbox is full. The system administrator can change this behavior in WHM's Exim Configuration Manager interface (WHM >> Home >> Service Configuration >> Exim Configuration Manager).

  • Make certain that you track your quota usage. A mailbox with a full quota cannot receive mail.
    • The quota calculation does not include your mailbox's trash folder.
  • Due to mail server constraints, you cannot assign quotas greater than 4096 TB (4 PB). You must assign the Unlimited value for quotas that exceed this amount.
    • If the Maximum option appears instead of the Unlimited option, your hosting provider does not allow unlimited email quotas.
    • You cannot assign custom quotas that exceed the Maximum value.
  • The system calculates mailbox quota use every four hours. For this reason, you may not receive notifications immediately if an email account reaches or exceeds its quota.
  • You can select different file sizes, for example MB, GB, TB, and PB.
  • Only enter whole numbers.
Thank you.