What is that gobbledygook at the bottom of your mail?

A few months ago I made a change to my mail client, something that I had been dithering over for years since getting on the Internet. Now, when I send out text e-mail (I avoid using HTML-based mail for good reasons.), this tool adds a long, seemingly patternless, string of strange characters at the bottom of my mail. People have been asking what that is. It’s my PGP digital signature (Which is related to my PGP public key.) and I’ve been meaning to have one for many years. Anyone else who uses PGP can now exchange public keys with me and we can send encrypted mail to each other. Very useful for sending passwords, credit card numbers and other privileged information. Given that I am paid to worry about this stuff, I figured I should practice what I preach.