It’s unusual for mail servers to suddenly start rejecting messages internally and from external sources. That’s exactly what I saw though over the weekend. A mailserver running mdaemon on Windows 2000 was rejected ALMOST every message that was sent it’s way whether it was an internal mail sender and recipient or external sender to internal recipient. The really interesting things was to see a message sporadically succeed. This problem was with mdaemon, but could have occured with ANY mail server. Here’s why…
Tag: blacklist
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Why? (Why couldn’t AT&T make sure their mail servers weren’t using old dialup IPs that are blacklisted….)
Why do I always wind up being the one to discover problems? …. Today in checking mail I found a mail that had bounced back from one of my clients that uses bellsouth… Now bellsouth has recently been bought by AT&T and it appeared as though the mail had been rejected because the mailserver trying to deliver it was in an email blacklist. *(What – a bellsouth mailserver in a blacklist?) Well, we’ve gone through this before with some of the passive blacklists where people might relay junk through their isp, but… on searching the AT&T outbound mailserver 207.115.11.54 was in the dial up block lists at sorbs and nomorefun…. (as was 207.115.11.55) These seem to be the new fmailhost04.isp.att.net and fmailhost05.isp.att.net outbound mail machines.
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More postfix spam blocking and Whitelisting….
I almost forgot to pass along a link to a more comprehensive detailing of postfix’s anti-uce controls…. here. Also, in the last article I briefly mentioned whitelisting. IF you intend to have several blacklists active it will pay to learn how to whitelist before you HAVE to. To do so, I simply created a text file at /etc/postfix/whitelist and int hat file you enter IP address or hostname followed by OK…. like this….
1.2.3.4 OK
goodmachine.com OKBut… of course, there’s a bit more.
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More postfix spam blocking….
Postfix has a NUMBER of tools for rejecting unwanted messages before they get in the door and waste your CPU time on deciding “hey this mail is spam”. Up until recently I’ve mostly used the relays.ordb.org check (which in the last couple months has now gone defunct.) When we started noticing problems with ordb.org’s responsiveness I planned to investigate other blacklisting options and found several. Obviously there are advantages and disadvantages to blacklisting. The first disadvantage is you have turned over control of blocking mail senders to an outside authority and you should familiarize yourself with THEIR policies for listing (and delisting) a server.
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Firewire/USB card and ethernet incompatibilities on Ubuntu 6.06
I’ve had a machine for quite a while that I’ve been working on as a “backup server”. My goal with it is to have a RAID1 setup with two 250GB drives and I also wanted USB2/firewire functionality so that I could even add a USB drive to the array for the purpose of having a hot-swapped spare drive that could be taken offsite. Well, the biggest frustration I’ve had has not been with software raid, or any of the rest of the software setup, but that something about the firewire/usb card didn’t like the built in ethernet. I FINALLY got things working… let me document what I went through.
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New variation of Sober virus coming in January
Now, we seem to be getting “coming attractions” previews in virus-land…. Anyway, I’ve read at several sources that we are to expect a new variation on the sober worm around January 5th, 2006. It’s said that the date was chosen to mark the formation of the Nazi Party. In the past, variants have spouted pro-nazi sentiments and redirected users to pro-nazi web sites.
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Google not talking to cnet?
According to the tail end of this article, Google has decided they are not talking to CNET new reporters until July 2006. Yet another good example of why it’s a good thing to have competition in the online search market.
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