When navigating to "cPanel » Spam Filters" and attempting to perform any modification changes, you may encounter a similar error:
Error: “/usr/bin/doveadm” reported error code “68” when it ended:
doveadm($USER): Error: Mailbox INBOX.$USER@domain_tld:
Failed to lookup mailbox status: Mailbox doesn't exist:
The error indicates that while attempting to load the configurations for certain email users, it was found that the user did not exist. This can happen if an email account was not removed properly or something caused the removal process to leave cruft behind.
Verify that the email address reported in the error log is an account that was meant to be removed.
Please note, if the reported failure describes an account that should exist, then a restoration from a backup will need to take place, as this error indicates that the symlink for the mailbox no longer points to a valid path.
Locate broken symbolic links with the following command:
find /home/$USER/mail/ -maxdepth 1 -xtype l
Use the "unlink" utility to remove the broken links found by the previous command.