Re: [Asrg] Re: 6. Proposals: LMTP vs. rDNS / Reverse MX [RMX] proposals

["Tomi Panula-Ontto" <tomi@panula-ont.to>]

----- Original Message ----- 
From: "Matthew Elvey" <matthew@elvey.com>
To: <security1@awot.fi>
Sent: Friday, November 28, 2003 7:06 PM
Subject: [Asrg] Re: 6. Proposals: LMTP vs. rDNS / Reverse MX [RMX] proposals


[cut]
> >MTAMark draft tells us the problem (from the spam point of view),
> >and they have done great job, but I think it's a little too complicated
> >to maintain. It may require configuration per domain if virtual
> >domains have their own MX setup (this does not apply to all setups).
> >Also, I don't like parsing TXT records (Parsing == bugs == troubles).
> >Bind and Tinydns seem to differ in TXT records, too. Some Bind versions
> >send extra character (space or ") (parser bug?) whereas Tinydns doesn't.
> >Conclusion: I'm against TXT records.
> >
> >
> A bug in the TXT part of software that has known security holes and MUST
> be replaced anyway isn't a deal breaker, IMO; I'm assuming these bugs
> are only in old versions.

It's easy to say "must", but lot harder to get all the servers upgraded.
It isn't deal breaker; MTAMark has very good qualities (and I think I had
a little misunderstanding on my side here about it).

> >RMX records (Do not confuse with Reverse MX records) is domain specific.
> >It's simply a list of IP addresses that can send email from some domain.
> >In reality, some of the users may use just about any sending SMTP
> >server [depending on their ISP]. For example,  I have a client that
> >operates in couple of countries, each using different ISP, yet the
> >incoming MTA is always the same, outgoing MTA is never the same.
> >They could be using SMTPAUTH, but instead they use email server
> >of ISP to send out messages. Do you think I could do something
> >about it? Should I administrate a list of outgoing mail servers for my
> >client in this case? No. It's not my job, so I'm against it and I believe
> >most of the administrators are against it. Also, RMX requires new
> >record type, that some bind versions refuse to send out.
> >
> >
> Argument built on a false foundation.  Your client isn't using "just
> about any sending SMTP server".  A short list of the IPs of the SMTP
> servers of the two (or 20) ISPs your client uses is 0.0% of the SMTP
> servers on the 'net.

Well, I'll give an example: client operates in more than 20 countries, has
travelling salesmen and agents in many countries. Yet, they all use same
email domain and everyone uses their current ISP to send out messages.
Notice: Travelling salesman maybe connecting even from hotel network.