Two interesting posts from Omar Shahine.

He discusses IMAP client development issues he encountered while implementing IMAP support in Microsoft's Entourage (?) and has this to say about Thunderbird (Mozilla e-client still in development):

Thunderbird is an almost perfect IMAP client for Windows. If you use IMAP, this is the product for you.

He also points to a nice table showing the effect of HTML DOCTYPE settings on the CSS Box Model (read layout depends on DOCTYPE).