I've got problems on outoing mail via sendmail. Some ISP's smtp servers (not all), dump any outgoing mail I send into the 'junk' or 'spam' folder of the recipient, so they seem to think that I am sending spam.
I have configured (with eg. example.com as my domain) :
- 'A' DNS domain records, so my domain can be recognised via dig/nslookup looking up my hostname example.com,
www.example.com or just exmaple.com
- 'A' record for my mail server server.example.com so it can be referenced from mx record immediately below
- 'MX' (mail) record for server.example.com immediately above, so that mail servers can lookup example.com and find a valid mail server.
- reverse dns for server.example.com so mail servers can lookup ip address eg 1.2.3.4 and find out it resolves to server.example.com (my mail server).
I have set up sendmail masquerading so any mail appears to come from eg. (anyuser)@example.com.
Some ISPs deliver successfully to the recipient.. some treat it as spam.
Is there anything else that needs to be configured so that ISP's mail servers recognise emails as non-spam messages ?
I have looked up my domain on dnsstuff.com, and it reports a valid domain, with valid mx record, with valid reverse dns lookup, and my ip address is not on a list of recognised 'spam' ip addresses. So in theory, all should be ok (?)
There's obviously something I've missed.. any ideas ?
(Also just added an spf TXT record in, with no luck)
Many thanks,
Jonathan.
Extra Info and Diagnostis (23/11):
This is is an example of a message which ends up in the junk folder, with example.com being my domain with IP 1.2.3.4, someprovider.com/5.6.7.8 being the domain of the recipients's provider, and 5.5.5.5 being the adsl provider connection through which the mail is being sent.
You can see that I'm using SMTP AUTH over SSL (by the crypto stuff) for example.com to verify that the sender has an account and is allowed to send outgoing mail (ie to prevent relaying). I doubt this is the cause though.. the SMTP handshaking at the protocol level looks fine. Sendmail reports:
Nov 22 22:56:44 server sendmail[26031]: jAN6ubVI025216: to=<recipient@someprovidercom>, ctladdr=<jon@example.com> (1001/100), delay=00:00:03, xdelay=00:00:02, mailer=esmtp, pri=121270, relay=mail.someprovider.com [5.6.7.8], dsn=2.0.0, stat=Sent (ok dirdel)
Now here's the junked message as received by the recipient
From Jonathan Tue Nov 22 22:59:48 2005
X-Apparently-To:
recipient@someprovider.com via 5.6.7.8; Wed, 23 Nov 2005 06:59:49 +0000
X-SomeProviderFilteredBulk: 1.2.3.4
X-Originating-IP: [1.2.3.4]
Return-Path: <jon@example.com>
Authentication-Results: mail.someprovider.com from=example.com; domainkeys=neutral (no sig)
Received: from 1.2.3.4 (EHLO server.example.com) (1.2.3.4) by mail.someprovider.com with SMTP; Wed, 23 Nov 2005 06:59:49 +0000
Received: from MYLAPTAP(some-dynamic-ip.a.provider.fr [5.5.5.5]) (authenticated bits=0) by server.example.com (8.13.3/8.13.3/SuSE Linux 0.7) with ESMTP id jAN6ubVI025216 (version=TLSv1/SSLv3 cipher=RC4-MD5 bits=128 verify=NO) for <recipient@someprovider.com>; Tue, 22 Nov 2005 22:56:41 -0800
Message-ID: <000a01c5effb$8195e000$6501a8c0@LAPTOP>
Reply-to: "Jonathan" <jon@example.com>
From: "Jonathan "
jon@example.com
To:
recipient@someprovider.com
Subject: testing test... at 08:00
Date: Wed, 23 Nov 2005 07:59:48 +0100
MIME-Version: 1.0
Content-Type: multipart/alternative; boundary="----=_NextPart_000_0007_01C5F003.E004B460"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2900.2180
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2180
Content-Length: 758
test
