Fix a full mailbox in cPanel: Email Disk Usage and quotas

When a mailbox reaches its quota, new messages bounce back to the sender with "mailbox quota exceeded" and the account may stop sending too. cPanel gives you two tools to fix it: Email Disk Usage to delete old mail by folder, and the quota setting in Email Accounts.

Before you start

• Access to cPanel, or ask the mailbox owner which folders they can live without.
• If the mail is important, back it up first: in an IMAP email app drag old folders to a local archive, or download a copy from JetBackup.

Check which mailboxes are full

1. Open cPanel → Email → Email Accounts.
2. The Storage: Used / Allocated / % column shows usage. Accounts near 100% are highlighted.
3. Click the column header to sort by usage.

Clean up with Email Disk Usage

1. Open cPanel → Email → Email Disk Usage.
2. Choose the account from the Account drop-down. You see each folder (Inbox, Sent, Trash, Spam, custom folders) with its size and message count.
3. Click Manage next to a big folder and choose an action, for example:
   • Messages older than 1 year
   • Messages larger than 10 MB
   • All messages (good for Trash and Spam)
   • Default: messages in the Trash folder older than 30 days etc.
4. Click Delete and confirm. The deletion is permanent.

Raise the quota

1. In Email Accounts, click Manage next to the account.
2. Under Allocated Storage Space, enter a larger value in MB or choose Unlimited.
3. Click Update Email Settings.

Unlimited still counts toward your hosting plan disk limit. If the whole account is out of space, see find what uses disk space and inode and quota limits.

Prevent it happening again

• In Roundcube, Settings → Preferences → Server Settings: tick Flag the message for deletion off and set Clear Trash on Log out.
• Enable Auto-Delete Spam in Spam Filters so spam does not pile up.
• Do not keep large attachments in the inbox; save them to cloud storage and delete the message.
• If you use POP3, tick "Leave a copy on server" only with "Remove after 14 days".

Troubleshooting

• Usage does not drop after deleting in an email app: the app moved mail to Trash, or it only flagged messages. Empty Trash and use "Compact" or "Expunge".
• Quota shows full but folders look small: the usage cache is stale. It refreshes within a few hours; contact support if it does not.
• Cannot send mail: some apps fail to save to Sent when the box is full. Free space first.

Next steps

• Manage email accounts
• Restore deleted email from JetBackup
• Check bounces with Track Delivery