[rt-users] email responses created separate tickets

[Vicki Stanfield]

I am a bit confused about emailed responses to rt tickets. First, I have 
an alias setup so that mail to sysadmin at domain.com comes into the local 
rt sysadmin queue. That seems to work fine. Now I have a situation where 
a user sent an email to rt which didn't get added as a ticket to rt (the 
cause is a network problem not an rt problem). I then responded to her 
email which still had the cc to the sysadmin queue, and the ticket got 
created. When another employee responded to my response, a second ticket 
was created instead of it being added to the ticket I created. Then the 
original sender replied, and a third ticket was created. What criteria 
determines whether a new ticket gets created or whether the email is 
appended to an existing ticket? Is it a ticket number in the Subject 
line or something like that? I have googled for the answer, but 
everything I have found has been either too high level to mention 
something so trivial or too low level to do so.

Vicki