Quotas on reseller accounts

Hi all,

I'd like to know if there is an easy way to find all users that are over quota and are no longer using there accounts.

I've inherited a cpanel/WHM system that is in a bit of a mess. I have several re-seller accounts and many cpanel user accounts also.

I am able to find the user accounts by using either # quota -su or looking at the /var/cpanel/repquota.cache file.
However the re-seller ones seem harder to get at, logging in as the re-seller I can see warnings for 3 accounts, looking at them I can see they have quotas set at 250MB for mail however one of them is showing over 800MB. I wanted to know is there a way I can list all re-seller accounts over quota or will I have to resort to some bash scripting to work it out?

On a side note does anyone know a way to establish if an account is in use? Currently my method is looking at the mail dir for the user, then drill down to the cur and new dir, I've been thinking if there are no files in cur or no files in new then they have been read and removed, yet if there are lots of files in new and they date back up to several years ago (2015 I've seen) then I assume no one is looking at them and the account is not active.

Cheers
Paul