Error – invalid maildirsize file

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:

  1. Login to your server via FTP
  2. Navigate to the following path /mail/yourdomain.com/user
  3. Substitute yourdomain.com/username with the correct email domain/user. E.G. user@yourdomain.com

  4. From this directory, delete the file named maildirsize
  5. Once this file is deleted, the system should reform the mail account automatically with the correct mailbox quota size upon new email activity.

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.