WREN's at Station X

If you are interested in cryptography or codebreaking, and have an interest in World War II, then you should try to get to Bletchley Park. I haven't been... yet. It is on my list of things to…

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Debugging MailScanner: cleaning messages

Last week I did a short post on testing MailScanner to be sure it was scanning properly. An alert reader pointed out that I missed the easy solution, which was to simply use 'MailScanner --lint' to check if MailScanner was running properly. Since I wrote that article, I found that my MailScanner was again hogging the CPU. Last time it was an issue with f-prot interaction, this time it is a problem apparently with MailScanner. Here is what I did to debug this issue, and here is the post that helped me learn more about MailScanner.

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Test your servers Virus filters - don't assume

On one of our RHEL5 servers running Ensim, we noticed after the last big update of RHEL using 'yum update', that MailScanner was capped out, using tons of our CPU power. In the past when this happens I usually find it is ClamAV acting up. However, we were using on this server a free version of f-prot. I took a chance and purchased the latest greatest mail server version of f-prot and installed it. Bingo, the problem went away.

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Email status messages - what do they mean

With one of my clients I need to monitor email bounces from our mailing lists. Normally this goes relatively smoothly, as either the email goes through, or it bounces back with a 550 Recipient not found message. Sometimes the messages I get back are less familiar to me. Here is the appendix from RFC1893.

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What is my IP Address

Lately I have been wanting to find what my outside IP address is. Videotron has recently started to actually expire the lease on my IP address more frequently than once a year, so I can't remember…

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