Did you ever forget to attach a file to your e-mail? Attachment Pro is a helpful addin for Outlook. Based on keywords in the mail body it will remind you to attach files before sending the message.
CreativixDB is a new database format based on the growing internet standard xml. within that, this project contains an sql interface for this database written for php, .net programs, office and java. the main great target is to create a groupware solution
Koolwired.Imap is a fully managed .NET IMAP client library written in C#.
Spamato is a spam filter system that combines several anti-spam techniques, from which thousands of users benefit. It is available as an add-on for Thunderbird and Outlook, and as a stand-alone proxy for other email clients. IMAP and POP are supported.
A better Webmail Interface for MailEnable.