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March 2, 2022 – 2:00 pm

Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …

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Extracting Email Addresses from TCP Streams

December 5, 2017 – 7:06 pm
shell

Here’s a quick example of using tshark to extract email addresses from TCP streams. Let’s say some application on your server is sending emails and you want to find out who is receiving those emails. …

Tracking Emails in Postfix Logs

October 27, 2016 – 6:02 pm
postfix_logo

Depending on your Postfix configuration, the same email may cycle through the postfix queue several times, changing it’s queue ID and making it difficult to track. For example, if you have Amavis configured for spam and …

Migrating email between hosted providers

May 23, 2008 – 9:38 pm
Postfix_logo

Recently I ran into a small problem. A customer of mine was moving her site to a new hosting provider. Her old provider was Windows-based and her new provider was Linux-based. The old provider did …