Mailbox Quotas & Storage

A mailbox quota controls how much disk space a single email account can use. Setting sensible quotas keeps individual mailboxes from filling up your whole hosting account and helps you spot problems before mail starts bouncing.

Setting a Quota

You choose a quota when you create an account, and you can change it any time afterwards.

Log into cPanel and open Email Accounts in the Email section.
When creating an account, set the Storage Space to a specific number of MB, or select Unlimited.
To change an existing account, click Manage, adjust the Allocated Storage Space value, and click Update Email Settings.

Tip Assign a reasonable quota (for example 1 GB) rather than Unlimited. A finite quota gives you an early warning when a mailbox is filling up.

Checking Usage

The Email Accounts page shows a usage bar for each mailbox:

Open Email Accounts in cPanel.
Each account lists its current usage against its quota, along with a percentage bar.
A bar that is turning red means the mailbox is close to full and needs attention.

What Happens When a Mailbox Is Full

When a mailbox reaches its quota, it can no longer accept new messages. Incoming mail bounces back to the sender with an “over quota” or “mailbox full” error, and no new mail is delivered until space is freed.

Warning A full mailbox silently rejects incoming mail. If someone reports that their messages to you are bouncing, check the mailbox usage first.

Freeing Up Space

To bring a mailbox back under its quota, remove messages you no longer need:

Sign in to webmail and delete large or old messages — sort by size to find the biggest offenders quickly.
Empty the Trash and Junk folders in webmail, since deleted and spam mail still counts toward the quota until it is purged.
Alternatively, connect an IMAP client (such as Outlook or Apple Mail), move older mail into a local folder, and remove it from the server.

Note Emptying Trash and Junk is often enough to recover a surprising amount of space. Deleted messages are only truly removed once those folders are purged.

How Email Counts Against Disk Usage

Email is stored on the server, so every message in every mailbox counts toward your hosting account’s overall disk quota. A few oversized mailboxes can quietly consume space that your website needs. Reviewing mailbox usage is part of keeping your total disk usage healthy.

When Mail Still Will Not Send or Receive

If a mailbox is within quota but mail still is not getting through, the cause may be elsewhere. See Email Not Sending for further troubleshooting, or open a support ticket.