Linux Administration Cookbook

See also

It's worth reading up on email because there actually is a good chance that you'll find yourself opening an email one day to look at the headers. Understanding why email works in the way it does (that is, handing off a message to the next mail server in a chain, until it eventually gets to the end user) can be very valuable in this context.

I may expand this section in the future, if the notion of running your own email server sees some miraculous resurgence.