How does one prevent auto-reply loops?

[Rudi]

Hi all,

I have searched the web and no suitable answer seems to be available? Say I am using Outlook via an exchange server. If I have an auto reply on and I get a reply from someone who's auto reply is also active, the two auto replies between these mailboxes are going to loop auto replies continually. Is these a known safe guard fro this issue for exchange; like a rule or an add-in that can prevent this loop?

TIA

[HansV]

As far as I know, the Exchange server will send an automatic reply only once to each sender.

[Rudi]

Yes, this is supposed to happen, but we experienced this issue recently where a user had over 10000 auto reply responses in his mailbox after a few days leave. I see on a google search that this is a issue for many users, yet there is very little said about a resolution?

One user says...
"I have created a auto-reply on one mailbox in exchange 2007 and some external ids are sending to this internal address and there is also auto-reply configured on one of the external id. This is creating a loop. one mailbox send a auto-reply to other and other is also reply by his auto-reply..."

If there is a known solution...please post it. TX

[Leif]

Exchange should handle this for you - an 'x-loop' header is inserted in the email header which should be detected and prevent an auto-reply to an auto-reply.

I can't find any clear explanation myself - the best I can find is Mail loop detection - ISS Home - Newcastle University which may give you an idea how it works.

If you can examine the header of an incoming auto-responder, you may also find fields such as:
Content-class: urn:content-classes:mdn
which in this instance defines it as a Mail Delivery Notification which should not trigger an auto-reply

[HansV]

The user should use the built-in Out-of-Office feature, not set a rule that automatically replies to all incoming messages. Out-of-Office should prevent multiple responses to the same recipient, but a user-defined rule won't.