If you're experiencing the following error: invalid maildirsize file on your server when changing a quota in the email accounts section of your cPanel, your mailbox may be corrupt. The "invalid maildirsize file" error can be easily corrected 99% of the time by following this simple solution. Implementing this fix is easy and only takes a couple of minutes as long as your comfortable managing files via ftp. So let's get started.
How to fix the invalid maildirsize file error:
- Login to your server via FTP
- Navigate to the following path /mail/yourdomain.com/user
- From this directory, delete the file named maildirsize
- Once this file is deleted, the system should reform the mail account automatically with the correct mailbox quota size upon new email activity.
Substitute yourdomain.com/username with the correct email domain/user. E.G. user@yourdomain.com
Notes: If the correct mailbox quota is still not being displayed, from within cPanel, you can navigate to email accounts and click the change quota button to set a new quota.