Webone blocking port 25??

Conrad Canterford conrad at mail.watersprite.com.au
Fri Jul 26 00:54:39 EST 2002

On Thu, 2002-07-25 at 20:19, Jeremy wrote:
> > Not true. You can be assured that webone at least are checking the IP
> > range the email comes from and not the name stated in the From:
> > header.
> > I know this, because my mail goes through their server, but my domain
> > is
> > not in any way set up by them or administered in any way by them. They
> > don't have any knowledge of it.
> Complete and utter bullshit.  A week ago I received a message from the 
> webone technical support explaining that my mails were being dumped 
> because they had an invalid domain in the from line.
> You might mean that webone are checking that the name in the From: line 
> contains a valid domain name.

Not complete and utter bullshit, actually. If all they were doing was
checking for a valid domain in the From: header, they would still be an
open relay (any script kiddie or spamster can invent a
randomcharacters at yahoo.com email address which will pass that test). Try
relaying through webones smtp host using a real hostname from outside
the webone network, and I'll bet you go nowhere (if you don't, I suggest
phoning webone immediately and pointing out to them that they are going
to be blacklisted really soon if they don't fix it).

As *additional* protection, they may well be checking that the domain
name in the From: header is a valid (resolvable) host name, but that's
more to stop stupid virii from propogating (and conveniently catches
many spamsters as well). It certainly doesn't stop them being an open
relay. Actually, I thought this was default behaviour with sendmail but
I really don't remember why I thought that.

In response to Rasjid, all I can say is that we must be on a different
plan. My inbound mail is still working and I hope it continues to do so.

Conrad Canterford  (conrad at mail.watersprite.com.au)
Water Sprite Pty Ltd   |  url - http://www.watersprite.com.au/
GPO Box 355,           |  - Australian Tour and Event Management (ATEM)
Canberra, ACT 2601     |  - Ticketing Division.
Mobile: +61 402 697054 |  - Catering Services Division.

More information about the linux mailing list