How much do you know about the mailto: URI scheme? I've just had cause to read RFC 2368, and I've learned a few things myself. Using the mailto URI scheme, you can:
Not very long ago I wrote to you concerning the mailto: URI scheme, which is used for initiating a new e-mail message. Today I shall show you how you can use URIs to reference existing e-mail messages (or content parts of a MIME message), so long as they are in the users e-mail store. This can be useful for cross-referencing e-mail messages in mailing-lists... if it's supported by your software.
In my research into URIs, I came across a useful tool for parsing generic URIs into their five major parts: scheme, authority, path, query and fragment. I've found it useful for increasing my understanding of URIs.
You can find uri_test.pl on the (Concluded) IETF URI Working Groups' old website. It's a reference parser written by Roy T. Fielding. You feed it a list of URIs and it breaks them up and spits them out.