Re: SMTP SSL on Port Other than 25

On Sun, 07 Aug 2005 22:12:05 -0700, Mark Olbert wrote:

> I've just spent six frustruating hours trying to get Outlook XP to
> use SSL/TLS over SMTP on a port other than 25. Why? Because the ISP
> I use when I travel - AOL - has some idiot system in place that
> redirects any attempts to connect to any computer's port 25 to their
> own mailservers. So I can't access my personal mail server from on
> the road.

Normally, I would just let this post go by because I don't have enough
expertise with MS Outlook to offer a solution. However, your comment on the
"idiot system" deserves a comment: it is not an "idiot system". RFC 2821,
and its predecessor, RFC 821, describe the SMTP protocol. It is an
unauthenticated message transfer protocol, which permits any SMTP client to
connect to any other SMTP server to relay email to a destination. Alas,
this lack of an authentication mechanism has made it too easy for spammers
to subvert the SMTP system for their own purpose.

Those who write these RFCs foresaw this problem at least as far back as
1998, the date on RFC 2476. This RFC defines a Message Submission system
which allows for authenticated connections by Message Submission Agents
(MSA), of which MS Outlook is an example, to Message Submission Servers.
This system is designed to work on port 587, and may, or may not require
STARTTLS (not the same thing as SSL) during the message submission.

Many ISPs, including my own (SBC Yahoo! DSL Service) are moving toward this
system. Comcast is going their own way, using port 465 for authenticated
message submission. SBC is also blocking port 25 except to their own
servers; but they are not redirecting, as AOL is doing. This is going to be
common for most U.S. ISPs in the near future. It is not idiotic, it is a
proven way to beat the proxy spammers. Proxy spam from compromised SBC
customer computers is less than 1/10the of the level prior to their
implementation of port 25 blocking.

As I said, I am not especially familiar with MS Outlook. It appears to have
very similar configuration issues as MS Outlook Express. I am told that
MSOE only does STARTTLS on port 25. Bummer. I saw no indication that MS
Outlook SP3 offers STARTTLS as an option on ports other than 25. Bummer.
MSFT is just going to have to get with the program; the Internet is not
their invention, and they still don't have control over how it works.

In the meantime, GMail does offer SMTP access through port 465 with SSL; I
know that MS Outlook Express works with that (I have tested it). MS Outlook
should also work with that.

--
Norman
~I'll be there, by your side
~in the land of Twilight.
~In your dream I will go
~'till we find the Sunlight.
.

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