On Fri, 5 Oct 2001, Dave Crocker wrote:
>(2) Store, in the MTA, the Message-IDs of messages passing.
here, to, the problem is that the message can legitimately transit
the same site more than one time.
My own sense is that counting the number of Received headers citing the
local system's domain name, and then bouncing messages that have more than
N such headers. Offhand, 3 seems safe, though 4 is probably just as
effective and more safe.
This depends entirely on the system in use and current architecture.
Although I agree that 3 or 4 is probably fine for Sendmail-based
systems I, for example, use 12. This is because for each step through
my system a message gets another Received: line, which of course has the
local system name in it. This is an architectural choice, the principal
benefit of which is simplicity of configuration and change.
Also, although I do maintain a Message-ID: database for recent messages
for loop control, the most common looping problem I encounter is sites
that set their address or their MX to 127.0.0.1.
Any ideas on how to deal with that?
Jim