[ On Wednesday, October 22, 2003 at 10:59:58 (+0200), Giuliano Gavazzi wrote: ]
> Subject: [Exim] DNS related probs.
>
> I do not agree! I know it's a question of opinion, but id Exim knows
> that the helo name is genuine as it corresponds to the host address,
> wouldn't it be better to set the sender_host_name to the
> sender_helo_name?
I'm not sure exactly what Exim does with sender_host_name and
sender_helo_name, but if they're used in composing the "Received:"
header then you don't want to mess with them.
The SMTP standards require that the name given to the greeting command
be used as the "from" name in the received header.
Unfortunately Exim _still_ gets this backwards in the received headers
it generates by default, but that can, and should, be easy to fix.
By convention the IP address is included in the comment following that
name, and also by convention if, and only if, the reverse DNS gives a
different name (ignoring character case) then it should be also included
in the comment as well, prior to the IP literal. Other information that
can be used to correlate the message to log entries may also be
included, such as is shown in this fragment of a the received header
generated by my mailer when it received your posting from this list's
mailer.
Received: from exim-colo-01.whoc.theplanet.co.uk([195.92.249.251] port=50399)
In this case the reverse DNS matches exactly:
$ host -i 195.92.249.251
251.249.92.195.in-addr.arpa PTR exim-colo-01.whoc.theplanet.co.uk
so my mailer did not include the PTR target name in the comment. Had it
not been the same, and yet was still allowed, then the result might have
looked a bit like this (manufactured from information in the other
headers of your posting):
Received: from mailhost.humph.com(dsl-217-155-139-146.zen.co.uk[217.155.139.146] port=63730)
So, in other words, if you mess with sender_host_name then you may
destroy valuable informatoin that should be included in the received
header!
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
