Showing posts with label Postfix. Show all posts
Showing posts with label Postfix. Show all posts

May 22, 2007

CBL Black listing

A few day ago, something weird happened to me, my mail server which uses SMTP authentication was listed in CBL, and as a result of that also in spamhaus.

I spent time reviewing, reading sending mail, trying to find out what was wrong with my server since CBL just told me "In short, this IP is impersonating being a machine we know it cannot be. No properly configured mail server does this under any circumstances." It was hard for me to find the problem.

I checked my maillog form start to end and everything seemed right, then I checked which ports I had opened, and same thing all was ok. Then I started doing some google search about CBL listing I just got references saying it did not give a clear response why you get blocked. To some extent it was like being eyes folded.

After reading manual, instructions and many other stuffs I realized that my server name was incorrectly set up at first, I fixed the problem but it kept getting listed. So I kept looking, until I found that one of many sited made reference to DNSSTUFF dns report, which actually pointed some mistakes for my domain. I fixed them and it almost my third day and I haven't got blocked. If you are running virtual domains I will suggest you to run dns report for each one of your domains. Make sure that you IP has a reverse DNS set correctly.

Apr 19, 2007

Postfix on fedora core 5

It's likely you are looking for a good tutorial that will teach you step by step how to install postfix with virtual users and smtp auth in order to avoid unauthorized SMTP relays.

Well I have installed postfix on a fedora core 5 box using a manual posted at howtoforge.com.

This tutorial will take you step by step, certain thing might fail (postfix compilation failed on my server so I downloaded the rpm provided by the tutorial) but yet, it will tell you what to do in that case.


In case that you don;t find a solution to a problem in the manual you can go to forums and post your problem and in less than a day you get a response from howtoforge.

The tutorial links is this. enjoy it:

http://www.howtoforge.com/fedora_virtual_postfix_mysql_quota_courier