"mairix is a program for indexing and searching email messages stored in maildir, MH or mbox folders."

Calling this tool a validator seems... optimistic?

"The Email Standards Project works with email client developers and the design community to improve web standards support and accessibility in email."

a UI for reading mailing list via a random find from #whatwg... storing away for the heck of it.

RFC 5322, released October 2008 is now the most up-to-date reference point for the Internet Message Format.

"Here's how to subscribe to mailing lists with a combined total posts of 2000 or more per day, and live. It's all about pattern recognition."

"Seek adds faceted browsing features to Mozilla Thunderbird and lets you search through your email more effectively."

Kellan does it again!

New email client for the Nokia Internet Tablet series (works on n800 & n810 models with IT 2008)

Sup is a console-based email client for people with a lot of email. It supports tagging, very fast full-text search, automatic contact- list management, custom code insertion via a hook system, and more.

Thunderbird, meet OS X's Address Book. (There's a download that patches support into Thunderbird 2 in there. Woo!)