[HECnet] TOPS-20 outgoing mail relay config

[Mark Abene]

On Sun, Feb 2, 2014 at 7:42 PM, Bob Armstrong <bob at jfcl.com> wrote:
  Comcast is evil.   Evil....   My first suggestion would be to get a real ISP
:-)

Unfortunately my two choices for Internet in San Jose are Comcast and
AT&T Uverse.   And being that Uverse is a totally unknown quantity, I'm
hesitant to gamble with switching.   :)


  Having said that, how about setting up a Linux box as a relay on your own
internal network?   It can accept incoming SSL mail on, say, port 465 and
then just forward it over your local network to TOPS20 on port 25.   Or does
COMCAST block port 465 too?

Incoming is no longer an issue, just outgoing.   For the incoming, I
created a postfix transport on an external mail server that I control
out on the net, which sends incoming mail to my DDNS address on an
alternate (unblocked) port, which my firewall forwards to port 25 on
TOPS-20 and all is well.   Outgoing mail is another story, since
Comcast blocks outgoing to any destination port 25.   This is a little
trickier, hence why I asked about the mail relays internal to HECnet.
In the meantime, I'll see if I can create an outgoing rule in my
firewall to send all outgoing TOPS-20 mail to the same external mail
server, which I can have listen on another port in addition to 25 and
serve as a smarthost.

-Mark



Bob


-----Original Message-----
From: owner-hecnet at Update.UU.SE [mailto:owner-hecnet at Update.UU.SE] On Behalf
Of Mark Abene
Sent: Sunday, February 02, 2014 7:12 PM
To: hecnet at Update.UU.SE
Subject: [HECnet] TOPS-20 outgoing mail relay config

Long story short: after moving to the other side of the country a year ago,
I finally (recently) had time to get my TOPS-20 system (KLH10) back up and
on HECnet.   Only to discover that Comcast (cablemodem service), in their
wisdom, blocks port 25 in and out, in an effort to "combat spammers".
This rather complicates my e-mail setup in TOPS-20.   For incoming, I simply
created a transport relay on an external mail server that I control in order
to deliver mail on an alternate port number that isn't blocked, and then
simply port forward it from my firewall to tcp port 25 on the TOPS-20
server.   That was the easy part.   Outgoing mail from TOPS-20 is proving to
be a bit more difficult.   I was thinking I may be able to intercept all
outgoing traffic from TOPS-20 bound for port 25 at whatever smtp server, and
redirect it to a single smart host (mail server on the net which I control),
on an alternate port that isn't blocked.   Might work.
The reason I'm asking about this here, is I'm curious given the mail
transports at LEGATO and CHIMPY on HECnet, if anyone has tried simply
setting one of them up as a "smarthost" relay for all outgoing mail in
TOPS-20, perhaps via the <mail>mailer-relay-info.txt config file.
Unfortunately the syntax of mailer-relay-info.txt is a little confusing;
despite the explanation in the file's comments, there are no clear examples,
and trying to follow the logic of the options in the MMAILR MACRO assembly
code is less than helpful in modern mail server context (transmogrify??
who's domain??).
Any suggestions welcome.

-Mark