SOLVED Maximum Mailbox Size Advice

martin MHC

Well-Known Member
Sep 14, 2016
214
35
28
UK
cPanel Access Level
Root Administrator
I am trying to find a definitive answer to the upper limits of mailbox size management on WHM (Version 70+) .

I have a client with a mailbox size of 18Gb (20Gb allotted space).

The client often complains of received emails not being received. This is almost certainly down to the client or other 3rd party issues (such as client mail browser), and is [probably] not the issue here, but I wanted to check what the upper advisable limits are for "WHM / Exim" mailboxes . This applies to IMAP connections rather than webmail apps.

I can't find (via a certain well known search engine as well as searching these forums ) any recent details about any upper limits and so wanted to confirm if there are such limits and what advice would be given by WHM for very large mailboxes of the ~15Gb+ size.

Or does it depend purely and only on the servers CPU / Ram capacity?

Cheers
Martin
 

cPanelLauren

Product Owner
Staff member
Nov 14, 2017
13,296
1,266
313
Houston
HI @martin MHC

I am trying to find a definitive answer to the upper limits of mailbox size management on WHM (Version 70+) .
I can't find (via a certain well known search engine as well as searching these forums ) any recent details about any upper limits and so wanted to confirm if there are such limits and what advice would be given by WHM for very large mailboxes of the ~15Gb+ size.
There are no limits on how big an email account can grow implemented by default. The only way to impose limits is through quotas. Larger mailboxes may experience delays when loading in webmail but this is to be expected due to the sheer size some of these can grow to. You may want to look at mdbox storage for some of these accounts that have email users with larger mailboxes. There's a great documentation page on this here: Mailbox Conversion - Version 68 Documentation - cPanel Documentation


Thanks!