I do NOT get any quota warning messages in zimbra (Release 7.2.0_GA_2669.RHEL6_64_20120410002025 RHEL6_64 FOSS edition.)

I created a test user and set his quota limit to 5 MB and sent a few mails.

under user's advance tab, i set it to ( Account quota (MB): 5 ) and save.

mailq show below output

(host mail.example.com [x.x.x.x] said: 452 4.2.2 Over quota (in reply to end of DATA command))

What's wrong with it.

I found below URls

Quota Warnings - Zimbra :: Wiki

The above is for ZCS 4.5

any help?