The warning notification of disk quota

Q: Is there anyway of sending a warning notification to users' that go over
their disk quota limit rather than locking them out?

A: By design, the user will receive message when he/she reaches the limitation or warning level and try to save data. However, you do have an option to select log event when a user exceeds their warning level. Then have 3dr party software send the log to the user.

Windows Disk Quota Overview

When enabling disk quotas, you can set two levels: the disk quota limit and the ... You can apply disk quotas to existing volume users by adding new quota ...
www.howtonetworking.com/server/quota0.htm

How to enable Windows Disk Quota

Right-click on the drive you want to enable quota. Select Properties. Click Quota. Check Enable quota management. Setup the quota accordingly. ...
www.howtonetworking.com/server/quota2.htm

Event ID 333

We have seen some cases regarding “disk quota”. If the user reaches the quota, it may generate event ID 333. Software may damage some system file such as ...
www.chicagotech.net/troubleshooting/eventid333.htm

System Exit Codes 1000 to 1999

1302 No system quota limits are specifically set for this account. ... 1453 Insufficient quota to complete the requested service. 1454 Insufficient quota to ...
chicagotech.net/troubleshooting/exitcode2.htm

System Exit Codes ove 10000

10068 Ran out of quota. 10069 Ran out of disk quota. 10070 File handle reference is no longer available. 10071 Item is not available locally. ...
chicagotech.net/troubleshooting/exitcode4.htm

Insufficient disk apce

Cause: disk space to users exceeding quota limit option is enabled under Windows ... Users who exceed their quota limit receive an "insufficient disk space" ...
www.chicagotech.net/server/quota1.htm