Email to Mailing List from 65.54.246.86 Rejected

I added a Hotmail email address to a mailing list for testing that mailing list. I found that messages from the Hotmail address were being bounced though, because the IP address of the sending Hotmail email server, 65.54.246.86, is in the Spam and Open-Relay Blocking System (SORBS) blocklist. SORBS is a DNS Blacklist (DNSBL). When I checked the SORBS list, it appeared that the 65.54.246.86 had been there for at least a week due to SORBS detecting spam orginating from the Hotmail email server at that address.

Database of servers sending to spamtrap addresses

Address:	65.54.246.87
Record Created:	Sat Aug 12 12:30:09 2006 GMT
Record Updated:	Fri Jun 1 19:30:05 2007 GMT
Additional Information:	[ Updated via: Spam 'o Matic ] Received: from bay0-omc1-s15.bay0.hotmail.com (bay0-omc1-s15.bay0.hotmail.com [65.54.246.87]) by desperado.sorbs.net (Postfix) with ESMTP id F0C6311466 for <[email]>; Sat, 02 Jun 2007 05:14:49 +1000 (EST)
Currently active and flagged to be published in DNS

I've been using SORBS as a blocklist for quite awhile, but I have encountered problems many times due to the fact that AOL, Hotmail, EarthLink, and email servers from some other large Internet Service Providers (ISPs) tend to get on the SORBS list frequently and stay there for a long time. I've contacted AOL and EarthLink support previously when I found one or more of their email servers were on the SORBS blocklist. I've found that, though the support personnel with which I communicated understand that their company employs blocklists or other means of blocking spam, they never seem to understand that other email providers may employ similar means. I've never been successful in getting the support personnel I've communicated with at AOL or EarthLink to take any action and usually it doesn't appear that they even understand the problem; I usually just get canned responses about how to stop their service from blocking email rather than any response indicating that they understand the problem is with email going from their systems to other systems (See SORBS Blocking AOL and EarthLink Servers and Report of SORBS listing to EarthLink).

I've found reports by others using SORBS of similar problems with email from Hotmail addresses (see Hotmail on sorbs?!?).

I understand that SORBS policy charging server owners to remove systems does drastically lessen the chances that systems will be removed quickly. I've considered removing the SORBS list from the blocklists I employ to reduce the deluge of spam in users' mailboxes, but it does block thousands of spam messages daily on my server, so I haven't taken that step yet. Usually, I add the sender's email address to the /etc/mail/access list used by Sendmail to keep email from particular senders being checked against the blocklists I employ.

In this case, though, I don't want any email addressed to the mailing list to be checked against a blocklist to preclude this problem. The Mailman mailing list software won't allow any email to the mailing list unless the "from" address is for a member of the mailing list, so I don't need the additional blocklist check.

Fortunately Sendmail, which is the software that handles email on the server, does allow you to specify that email to particular "to" addresses will always be accepted and won't be checked against DNSBL's. You can allow email to a particular address to bypass the blocklist checks by editing /etc/mail/access. Place a line similar to the following in that file:

To:jsmith@example.com         OK

The line above would ensure that email addressed to jsmith@example.com would not be checked against any blocklists employed on the email server.

After editing /etc/mail/access, you need to recreate the access database with a command similar to the following:

makemap hash /etc/mail/access </etc/mail/access

Once I added the mailing list address, I was able to send email to that address from the Hotmail account without worrying that the Hotmail email server used to transmit the messages might be on the SORBS blocklist or another blocklist I'm employing to limit spam.

References:

1. Spam and Open-Relay Blocking System
2. DNSBL
   Wikipedia, the free encyclopedia
3. SORBS Blocking AOL and EarthLink Servers
   April 23, 2006
   MoonPoint Support
4. Report of SORBS listing to EarthLink
   April 23, 2006
   MoonPoint Support
5. Hotmail on sorbs?!?
   Posted: September 21, 2005
   ReadList.com - Threaded Mailing List Reader
6. Sendmail cf/README - Anti-Spam Configuration Control
   sendmail.org

[/network/email/mailing_list] permanent link

Installing Yum on a RedHat 9 System

For a RedHat Linux 9 system, I wanted to install Yum, which is an automatic updater and package installer/remover for Linux systems that use RPMs to manage installed software. I checked to see if Yum was already installed, but it was not installed.

# rpm -qa | grep -i yum

The Yum Download webpage listed the requirements for the latest version of Yum, version 3.2.0, as python 2.4+ and rpm 4.3 and above. I checked the version of the python and rpm packages on the system, but found they were not at the required versions.

# rpm -q --last rpm python
rpm-4.2-0.69                                  Sat 08 Nov 2003 02:37:24 PM EST
python-2.2.2-26                               Sat 08 Nov 2003 02:37:22 PM EST

Instead I needed to get a much earlier version, 2.0.8, which only required python 2.1+ and rpm 4.1.1-4.3.1. After downloading the rpm file, I installed it with rpm --install yum-2.0.8-1.noarch.rpm. I then checked for updates for the system with yum check-update.

An update was available for tcpdump among other utilities. An rpm -q --last tcpdump command showed the following information for the version already installed on the system:

tcpdump-3.7.2-1.9.1                           Sat 08 Nov 2003 08:39:55 PM EST

I tried updating tcpdump with yum install tcpdump, but received the error message below:

# yum install tcpdump
Gathering header information file(s) from server(s)
Server: Red Hat Linux 9 - i386 - Base
Server: Red Hat Linux 9 - Updates
Finding updated packages
Downloading needed headers
Resolving dependencies
Dependencies resolved
I will do the following:
[update: tcpdump 14:3.7.2-7.9.1.i386]
Is this ok [y/N]: y
Downloading Packages
Getting tcpdump-3.7.2-7.9.1.i386.rpm
retrygrab() failed for:
  http://mirror.dulug.duke.edu/pub/yum-repository/redhat/updates/9//x86/i386/tcpdump-3.7.2-7.9.1.i386.rpm
  Executing failover method
failover: out of servers to try
Error getting file http://mirror.dulug.duke.edu/pub/yum-repository/redhat/updates/9//x86/i386/tcpdump-3.7.2-7.9.1.i386.rpm
[Errno 4] IOError: HTTP Error 404: Not Found

When I checked the Duke University wepage at http://mirror.dulug.duke.edu/pub/yum-repository/redhat/updates/9/x86/, I found it had only one file in that directory. So I needed to add another repository for updates to software for RedHat 9 systems. I found a list of such sites at http://fedoralegacy.org/download/fedoralegacy-mirrors.php. Many of those I checked in the US also no longer had the files available for download. But the DataPipe one at http://mirror.datapipe.net/fedoralegacy/ did still have files available.

I added the following line to the updates section of /etc/yum.conf

baseurl=http://mirror.datapipe.net/fedoralegacy/redhat/9/updates/i386/

The yum.conf file now has the following information in it:

[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
tolerant=1
exactarch=1

[base]
name=Red Hat Linux $releasever - $basearch - Base
baseurl=http://mirror.dulug.duke.edu/pub/yum-repository/redhat/$releasever/$basearch/


[updates]
name=Red Hat Linux $releasever - Updates
baseurl=http://mirror.dulug.duke.edu/pub/yum-repository/redhat/updates/$releasever/
baseurl=http://mirror.datapipe.net/fedoralegacy/redhat/9/updates/i386/

I then ran yum install tcpdump again and this time was able to update tcpdump. Checking the version of the rpm installed afterwards, I saw the following:

# rpm -q --last tcpdump
tcpdump-3.7.2-7.9.4.legacy                    Sat 09 Jun 2007 05:08:22 PM EDT

Yum 2.0.8-1 Download Sites

Duke University

MoonPoint Support

References:

1. Yellow Dog Updater (YUM)
   Linux@DUKE
2. RPM Package Manager
   Wikipedia, the free encyclopedia
3. RedHat 9 Updates - Using Fedora Legacy
4. Mirror sites by country
   The Fedora Legacy Project

[/os/unix/linux/sysmgmt] permanent link