[rt-users] RTAddressRegexp - not clear to me

[Joseph Spenner]

--- On Tue, 7/27/10, Mike Johnson <mike.johnson at nosm.ca> wrote:

>From: Mike Johnson <mike.johnson at nosm.ca>
>Subject: Re: [rt-users] RTAddressRegexp - not clear to me
>To: "Joseph Spenner" <joseph85750 at yahoo.com>
>Cc: rt-users at lists.bestpractical.com
>Date: Tuesday, July 27, 2010, 11:56 AM
>
>You need to include both, the queue email addresses, AND anything that >forwards email to RT.
>
>That setting prevents RT from sending emails that will "loop" infinitely >in your system.
>
>For example.
>
>RT is setup with the basic autoreply, and reply on correspondence etc.
>
>RT has 2 queues, support at here.com goes to general, and it at here.com goes >to IT queue.
> 
>If it at here.com emails support at here.com the general queue will autoreply >to it at here.com which will create a ticket and autoreply to >support at here.com which will create a ticket and auto-reply to it at here.com >etc etc etc....
>
> 
>Big loop, never ending, blow up RT :P
> 
>If you set the regular expression to support at here.com when RT emails out, >it'll filter any emails going to support at here.com.  This will ensure no >loop happens.
>
> 
>SO to recap, RTAddressRegexp has to be a regular expression that ALL >email addresses that send stuff to RT will validate through.
> 
>Hope this helps!
>Mike.

Mike:
  It makes sense, and I suspect my RT2 was vulnerable to this sort of thing.  But I've run it since 2001 and never had this happen.  But I can see how it could.  I would imagine people with evil "out of office" responders would/could create tickets as well, but I think most mail servers (even Exchange) is smart enough to only send 1 "out of office" message.

  So, what does RT do with the email/ticket if it matches?  Does it get silently dropped?

  Also, I ~thought~ sendmail/postfix was smart enough to kill loops (or prevent them from starting) based on the information in the email header.  Apparently not the case?  If RT doesn't retain any of that information, sendmail/postfix might see it as a new message every time..