port 25 forgeries

[Paul J. Ste. Marie]

At 11:35 PM 1/21/95 PST, santa at northpole.toad.com, org at toad.com wrote:
> ... 
>Received: from relay2.UU.NET by eri.erinet.com (4.1/SMI-4.1.1)
>	id AA16848; Sun, 22 Jan 95 02:56:29 EST
>Received: from toad.com by relay2.UU.NET with SMTP 
>	id QQxztg01780; Sun, 22 Jan 1995 03:01:32 -0500
>Received: by toad.com id AA23166; Sat, 21 Jan 95 23:55:03 PST
>Received: from northpole.org (tower.stc.housing.washington.edu) by toad.com 
id AA22783; Sat, 21 Jan 95 23:36:47 PST
> ...

Presumeably the (tower.stc.housing.washington.edu) comes from a PTR DNS 
lookup. What happens if the IP address of the remailer isn't available from 
DNS, or the in-addr.arpa entry is wrong?  (I don't know who exactly is 
responsible for the in-addr.arpa entry--is it the same as for the others?)

    --Paul J. Ste. Marie
      pstemari at well.sf.ca.us, pstemari at erinet.com