Email - 'Quota update failed, it's now desynced'

Installed with 'Perfect Server - Debian Wheezy (Apache2, BIND, Dovecot, ISPConfig 3)'

Email is being sent and received properly. Sent and received with both Thunderbird and Squirrel Mail.

However am receiving the following in logs which I've not been able to troubleshoot.

In both email warning and error logs:

Here's the directory listing:

Have searched manual and forum for a place to start correcting this even though email is transferring properly.

Cheers in advance for any guidance.

 

Results of
ls -la /var/vmail/works.eu/dolphin/

Code:

root@fluffybunny:~# ls -la /var/vmail/works.eu/dolphin/
ls: cannot access /var/vmail/works.eu/dolphin/: No such file or directory

Note:

When I first started following up on this, I've not seen either a file or directory with just the user name such as:

dolphin

Only have seen directories for asscoiated user:

dolphin.works.eu

 

Ugh. There's the problem.

Assume there is a bit of work involved after the edit.