On Fri, 21 Apr 1995, Anita Cohen-Williams wrote:
>     I have just gotten an error message from my LISTSERV stating that someone
> tried to sign on with an unknown domain. The information to the right of the @
> are all numbers (i.e. 192.245.137.1). The host postmaster doesn't recognize
> this and neither do I. I deleted the user since it will spawn countless error
> messgaes. Has anyone else run across this sort of thing before?
 
        The user is trying to use their IP address instead of an internet
domain name to subscribe to your list.  There's a few issues here:
 
1) 192.245.137.1 is an unassigned IP address served by feenix.metronet.com.
   IP addresses ending in .1 are typically routers or other control hardware,
   so trying to send email to [log in to unmask] doesn't make much sense
   if it's just the network router.
 
2) I think that if a user wants to specify the IP address of their machine
   in their email address, the correct form is user@[192.245.137.x].  I
   think this is in one of the internet mail RFCs, (possibly 822?).  I
   don't have enough experience with listserv to know if it's possible to
   handle an address of this form.
 
Lee Silverman     [log in to unmask]      http://www.netspace.org/users/lee/
Network: Any thing reticulated or decussated, at equal distances,
         with interstices between the intersections.  -- S. Johnson