🚀 go-pugleaf

In article <REID.93Jan27012619@dsm.dsm.fordham.edu>, 
reid@dsm.fordham.edu (Darin Reid) wrote:
> 
> Just wondering:  I foward my mail from machine A to machine B - Then I
> foward my mail frm machine B to machine A - what happens when someone
> sends mail to either account?
> 
> (I thought of this at 3:00 am, don't flame me - just curious to know)
> --
> Darin Reid
> 

You would create what is called an "alias loop," a notorious
problem with email.  In most systems there is some kind of hop
count parameter for just this reason.  What will probably happen
is that your message will bounce back and forth until the
hop count limit is exceeded, then get returned to sender with
an error message.  If your mailers are really brain-damaged,
the error message may itself bounce back and forth...

This is obviously a great way to create massive amounts of
traffic, especially since in many cases each pass through
a mailer will add another header to the message so the
bouncing message can get really long.

Some really clever mailers can detect that a message is
a bounce-back from such an alias loop, and stop this
nonsense.  One way is to look for your own header in the
message, and analyze any such headers you find to see
if such a loop is happening...


Matt Healy
"I pretend to be a network administrator; the lab
 net pretends to work!"

matt@wardsgi.med.yale.edu

In article <REID.93Jan27012619@dsm.dsm.fordham.edu> reid@dsm.fordham.edu (Darin Reid) writes:
>Just wondering:  I foward my mail from machine A to machine B - Then I
>foward my mail frm machine B to machine A - what happens when someone
>sends mail to either account?
>

Well, if you do this at 3:00 in the morning, you have a very angry system
administrator in your office at 8:01 (give him time to get into his office and
see his machines having problems).  We had a student here in our department
put *five* local hosts into his .forward file.  They merrily sent the message
to each of the five machine, which in turn sent to each of the five machine,
which.......  Needless to say, I was not a happy camper, as it was my first
day on the job and I didn't have the root passwords yet.  I had to find one
of the other people who had the password, get the password, and fix the problem.

At least, on the good side, I got the passwords that someone had forgotten to
tell me   ;)

Steve
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