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Email blacklisting
by Simon Giles at 17:33 20/11/04 (Forum::Technical Advice::General)
Have I become spam? Bruce has suggested I put this problem out to tender... Most of you know (of) me already, so it goes.
Apologies for indications of cringe-worthy incompetence that will follow (I'm no techie) but here's my first problem...

Seems I've been blacklisted by a mate's ISP, and both of us claim it's not at our end. My ISP is 1and1.co.uk and his is www.gen.net.uk and the suspect address is mplatten@genmail.net

Both ISP supports have been approached and they just fobbed me off with...

----- Original Message -----
From: "Richard Taylor" <Richard@gen.net.uk>
To: "'Billycan.org.uk'" <simon@billycan.org.uk>
Sent: Thursday, November 18, 2004 3:25 PM
Subject: RE: C27426571 Re: Email block...

Hi,

There are many filters and checks performed on incomming mail, and any one
of them could be the one. Here's a few idea's.

http://www.gensupport.net/KBShow.asp?Article=221

----- Original Message -----
From: <support@1and1.co.uk>
To: <simon@billycan.org.uk>
Sent: Wednesday, November 17, 2004 8:53 PM
Subject: C27426571 Re: Email block...

Dear Bruce Ure, (Cust: 6559055)

Thank you for contacting us.

The destination mplatten@genmail.net may have blacklisted your email
address, please check it with their providers for more information

If you have any further questions do not hesitate to contact us.

Kind regards
Mehdi Ali

[Note customer service technique, from Mohammed's brother, of addressing 'Bruce Ure', who kind of is my default 'system administrator'/bug assasin or blame sink.]

Any help on this puzzler would be good - although one less e-mate to answer might be a good thing.

Cheers

Simon G

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Email blacklisting Simon Giles - 17:33 20/11/04
Re: Email blacklisting Simon - 17:39 20/11/04
So what happens when you try to email your mate? Do you get a bounce message back or does it disappear into the void?

If you get some kind of error report, post it up here.
--
simon

Re: Email blacklisting Simon Giles - 19:14 20/11/04
Hi Simon as requested here was the first returned mail message:
--------------------------------------------
This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

mplatten@genmail.net
SMTP error from remote mailer after MAIL FROM:<simon@billycan.freeserve.co.uk>:
host reliance.gen.net.uk [213.249.192.9]: 572 billycan.freeserve.co.uk host name is unknown

------ This is a copy of the message, including all the headers. ------

Return-path: <simon@billycan.freeserve.co.uk>
Received: from [195.92.195.173] (helo=cmailg3.svr.pol.co.uk)
by fmailm2.svr.pol.co.uk with esmtp (Exim 4.14)
id 1C2VzN-0000Az-S4
for mplatten@genmail.net; Wed, 01 Sep 2004 15:21:29 +0100
Received: from modem-31.anfauglir.dialup.pol.co.uk ([62.136.109.159] helo=billycan1)
by cmailg3.svr.pol.co.uk with smtp (Exim 4.14)
id 1C2VzJ-0008MM-WC
for mplatten@genmail.net; Wed, 01 Sep 2004 15:21:27 +0100
Message-ID: <009a01c4902e$f8fde260$9f6d883e@billycan1>
Reply-To: "Simon D. C. Giles" <simon@billycan.freeserve.co.uk>
From: "Simon D. C. Giles" <simon@billycan.freeserve.co.uk>
To: "Mark Platten" <mplatten@genmail.net>
References: <5.0.0.25.2.20040826185303.01c59948@mail.genmail.net>
Subject: Nicked?
Date: Wed, 1 Sep 2004 15:21:19 +0100
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----=_NextPart_000_0097_01C49037.54F50000"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2800.1437
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1441

This is a multi-part message in MIME format.

------=_NextPart_000_0097_01C49037.54F50000
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

Hasn't your package turned up yet?

I'm off to Singapore tomorrow night - 9pm - so I'll be in touch.

Laters

S
------=_NextPart_000_0097_01C49037.54F50000
Content-Type: text/html;
charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META http-equiv=3DContent-Type content=3D"text/html; =
charset=3Diso-8859-1">
<META content=3D"MSHTML 6.00.2800.1458" name=3DGENERATOR>
<STYLE></STYLE>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV>Hasn't your package turned up yet?</DIV>
<DIV> </DIV>
<DIV>I'm off to Singapore tomorrow night - 9pm - so I'll be in =
touch.</DIV>
<DIV> </DIV>
<DIV>Laters</DIV>
<DIV> </DIV>
<DIV>S</DIV></BODY></HTML>

------=_NextPart_000_0097_01C49037.54F50000--
--------------------------------------------
And this was the last:
--------------------------------------------
This is the SMTP Server program at host me.freeserve.com.

I'm sorry to have to inform you that the message returned
below could not be delivered to one or more destinations.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the message returned below.

The SMTP Server program
<mplatten@genmail.net>: connect to reliance.gen.net.uk[213.249.192.9]: server
dropped connection

--------------------------------------------

Hope you can tell me what's going on. Cheers.
--
Simon G

Re: Email blacklisting Simon - 10:40 21/11/04
Here's the problem:

572 billycan.freeserve.co.uk host name is unknown

The mail has been sent from your local machine to Freeserve's inbound mailserver:

Received: from modem-31.anfauglir.dialup.pol.co.uk ([62.136.109.159] helo=billycan1)
by cmailg3.svr.pol.co.uk with smtp (Exim 4.14) id 1C2VzJ-0008MM-WC
for mplatten@genmail.net; Wed, 01 Sep 2004 15:21:27 +0100

...and then on to Freeserve's outbound mailserver:

Received: from [195.92.195.173] (helo=cmailg3.svr.pol.co.uk)
by fmailm2.svr.pol.co.uk with esmtp (Exim 4.14) id 1C2VzN-0000Az-S4
for mplatten@genmail.net; Wed, 01 Sep 2004 15:21:29 +0100

... which contacted Genmail's mailserver and said "I've got some mail for you from simon@billycan.freeserve.co.uk".

Genmail's mailserver rejected the mail with a 572 error, and the message 'hostname is unknown'.

Odd, that, since a 572 error is strictly 'Relay not authorised', not 'hostname is unknown' - and usually only happens when something tries to send mail via a gateway that doesn't accept, or relay, mail for the intended recipient.

Here's what I guess is going on - Genmail have got "VisNetic MailScan for SMTP" installed, a content-filtering mail gateway add-on (I've found this out by trying to connect to the mailserver for genmail.net by hand).

This software can be configured to reject inbound mail based on a number of tests, eg by doing what's called an MX lookup ("Is there a Mail eXchanger record that says there's a machine somewhere on the internet that's prepared to accept mail for the Sender's email address simon@billycan.freeserve.co.uk?" - to which the answer is 'yes') and/or an A record lookup ("Is there an IP address for a machine on the internet called billycan.freeserve.co.uk" - to which the answer is 'no').

From what I can tell, Freeserve advertise an MX record for your billycan.freeserve.co.uk address (it's a machine called mail-in.freeserve.com), but don't give billycan.freeserve.co.uk an A record (host not found). This is perfectly valid for them to do - the bit after the @ sign in an email address doesn't have to be a machine with an IP address.

The problem therefore is with Genmail's configuration of their inbound mail gateway - it's rejecting mail when it can't find an IP address for the domain part of an email address.

However, this bounce is from September and I've just tested the Genmail server by hand and it doesn't *seem* to be suffering the problem any more. If it was, it'd reject the following test with a 572 error immediately after the MAIL From: line

$ telnet reliance.gen.net.uk 25
Trying 213.249.192.9...
Connected to reliance.gen.net.uk.
Escape character is '^]'.
220 Welcome to gen.net.uk - MailScan ESMTP Server BUILD 5.2.86
EHLO anubis.novacaster.com
250-Hello anubis.novacaster.com! Pleased to meet you.
250-8BITMIME
250-DSN
250 HELP
MAIL From: <simon@billycan.freeserve.co.uk>
250 OK - mail from <simon@billycan.freeserve.co.uk>
RCPT To: <mplatten@genmail.net>
250 OK - Recipient <mplatten@genmail.net>
QUIT
221 Service closing transmission channel
Connection closed by foreign host.

What happens if you try to email mplatten@genmail.net from your Freeserve dialup account right now?
--
simon

Re: Email blacklisting Simon Giles - 12:46 21/11/04
Thanks Simon.
Have done as you suggested using all variants of sending I can do from here:

1)Via Freeserve dial up Pop account
2)Via Virgin dial up Pop account.
3)Via Oneandone dial up Pop account.
4)Via Virgin broadband to Pop account.
5)Via Virgin broadband to Oneandone Pop account.

...and nothing has been bounced yet! It's going to be one of those situations where the problem has mysteriously been sorted, and we'll never know for sure why it happened.

Did try sending to Freeserve Pop via Virgin broadband but got this:

The message could not be sent because one of the recipients was rejected by the server. The rejected e-mail address was 'mplatten@genmail.net'. Subject 'Testing7', Account: 'Freeserve', Server: 'smtp.freeserve.com', Protocol: SMTP, Server Response: '550 Administrative prohibition', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79
--
Simon G

Re: Email blacklisting Simon - 13:10 21/11/04
Good-o.

Regarding the one failure:

In general, if you're connected via one ISP then you have to send your mail through that ISP's mailserver.

Usually, the only exception is where you have an account on another ISP that lets you authenticate yourself on their mailserver in order to send mail.

Authentication can be done in any number of ways - SMTP username/password is common - but essentially you want to see if any of your ISPs support 'Authenticated SMTP', and if so you'll be able to (with a reconfig of your mail client) send all your mail through that ISP's mailserver, regardless of who you happen to be connected through at the time.
--
simon

Re: Email blacklisting Simon Giles - 21:48 21/11/04
Confirmed - all my test variables got through to the guy... could your investigation (for which many thanks) have caused the Gen people to unblock me from the filter? Or was it just sorted out at my mate's end by his ISP support getting off their arses and changing the filter at some indeterminate time recently, or after my last enquiry, or my ISP's potential chasing?

All amazing detective work nevertheless, me not being a code person etc.

--
Simon G

Re: Email blacklisting Simon - 22:42 21/11/04
I don't think there was a specific filter for your address, just a misconfiguration of one of the standard features of the software they were using to handle their inbound mail.

I reckon it's likely other people trying to mail in to their users from Freeserve must have had the same problem, which may have prompted them to review things sometime between September and now.
--
simon