[rt-users] why my rt4 loop create new ticket or reply ticket from the same email

[nectar]

Sir,

Upgraded from 3.8 to rt4 at debian6 + postfix, but my new rt4 create
new tickets from loop emails. For example, if people email "hello" to
rt4, then rt4 will created ticket #2, and after some minute, rt4 will
create ticket#5 or other new tickets with the same email content. More
emails are being sent out from rt, and most of them are the same
content.

I tried to check RT configure, postfix configure  and apache configure
files. Still can not find solution. Do you have advise?

Thank you.

--
Jia