Choose from the following resources or check below.
Are you receving this error when you are receiving mail from another account? Mailbox full error is shown when you exceed the amount of disk quota allocated to that particular mail account. All you need to do is allocate some more space to the account.
Follow these steps to fix the issue –
1. Log in to cPanel.
2. Check the disk usage at the left column and how much free space is available.
3. Goto Mail >> Email accounts.
4. Check for the mail account which is having the problem and it’s disk usage will be highlighted with red if the quota is exceeded.
5. Click change quota option. Increase the quota space based on the free space available and the hosting plan you are using.
6. Save the changes.
7. The email’s disk usage will be highlighted in green colour.
8. Now, try sending the mails to the email account which has exceeded the disk quota limit and you’ll be successful.