Manta mail is a client e-mail based on the win32 API.
Vivian Mail - A free mail client for SMTP and POP3-Server.
Mini Mail Server is a perfect solution for travelers.
Focus on inbox management, categorization of e-mails usig algorithms.
E-Mail client application for POP3 / IMAP / SMTP.
Automatically monitor one or more folders for specified files to send via e-mail