Popcorn
Popcorn is a freeware ultra-lightweight POP3/SMTP e-mail client. It works as a client or server application, reading mail directly from POP3 servers. It is ideally suited for on-the-road mail access, scanning, and reading and sending mail over slow connections. It supports multiple user profiles, enabling you to read, and send mail from any number of accounts. It requires no installation. It is ideal for cleaning up POP3 accounts, removing spam and unwanted mail and large attachments, and so on. It has a mail editor allowing you to compose and send new mail, and reply-to, forward, and redirect functions. It fits easily on floppy or other portable (even read-only) media.