Re: [Exim] Error from Exchange server

At 1:43 +0000 2003/02/08, Alan J. Flavell wrote:
>On Fri, 7 Feb 2003, Richard Welty wrote:
>
>[what seems to be the #1 FAQ for illegally-configured servers]
>
>> if you really have to accept this email (changing host names on NT boxen
>> can be a bastard of a job) there is a flag to permit _ characters in HELO
>> values.
>
>And you'll then be accepting a heap of spammer mail that you could
>have avoided.
>
[...]
> >From our rejection log, I can assure you that many of these defective
>domains are spammers and other kinds of email abuser. It really would
>not be a good idea to accept the lot of them without further protest.

oh yes? (In short, you will not necessarily avoid spam by being
strict as the HELO error can be ignored).

[ti:~] xfhjsf% telnet mailhost 25
Trying x.y.t.w...
Connected to x.y.t.w.
Escape character is '^]'.
220 x.y.t.w ESMTP Exim 4.12 Sat, 08 Feb 2003 19:10:38 +0000
helo a_b.ntl.com
501 Syntactically invalid HELO argument(s)
mail from: test @hotmail.com
250 OK
rcpt to: fsdlfjfds @humph.com
250 Accepted
data
354 Enter message, ending with "." on a line by itself
popo
.
250 OK id=HA07Y1-000E4Y-00
quit
221 x.y.t.w closing connection
Connection closed by foreign host.

apart from the obvious mailaddress/hostname/address masquerading,
this is a real smtp session. As you can see a real spammer can just
ignore this error. Indeed they do, while proper servers will stop
there. Not a very useful behaviour.

Now I will be flamed because I did not read the fine manual in
sufficient detail.

Giuliano