Although this has been a very common issue, I was unable to find any similar threads.
The Email account quota's do not restrict themselves to the Summary Disk Quota which has been allocated to the Cpanel Account.
This means that a user who has taken 50MB from me, still has the option to set the quota of all 5 of his email accounts to 250 MB each.
When any one of his accounts reach 50MB, his mails will stop, even though when he logs into the email account section in cpanel, he will see only 50 / 250MB used.
This tends to give a wrong impression to the user, especially if the email quota is showing unlimited or the max (2048 MB) and his actual cpanel disk limit is much less.
When allocating email account quotas, cpanel should dynamically be able to determine, how much actual space can be allocated.
Eg: If the cpanel disk quota is 1000 MB
After creating 1 email account of 250 MB, it should allow me to create the next email id with a quota of only 750MB or less.
If I have created 2 accounts of 500 MB, then it should not allow me to create a third email address, until I reallocate the space, so that there is no overspill.
I hope I am clear.
Any more thoughts on this are welcome.