Top 15 Free Email Services

Inbox.com not only gives you 5 GB to store your mail online but also a highly polished, fast and functional way to access it via either the web (including speedy search, free-form labels and reading mail by conversation) or through POP in your email program.
Unfortunately, IMAP access is not supported by Inbox.com, and its tools for organizing mail could be improved with smart or self-teaching folders.
Inbox.com Review | Inbox.com Tips

Lavabit nets you a solid, secure and privacy-conscious email account which you can access in your email program using POP or IMAP and in your browser using a rudimentary web interface.
It's a pity Lavabit restricts statistical spam filtering to paid accounts and lacks a fully fledged web interface.
Lavabit Review

Facebook Messages combines emails with everybody, conversations with Facebook friends and SMS texts in a single, simple place organized by the people with whom you communicate.
Facebook Messages's chasteness works well for a limited amount of personal mail, texts and messages, but to handle all your mail, Facebook Messages could do well with more robust tools for managing emails and contacts.
Facebook Messages Review | Facebook Messages Resources | Facebook Messages Tips

Myspace Mail adds an email address to your social network so you can exchange messages with everybody, not just MySpace members.
Unlimited storage lets you keep all the mail you like, but don't count on Myspace Mail helping you organize the messages — or your address book. It's also a pity Myspace Mail does not offer POP or IMAP access and cannot retrieve mail from external accounts.
Myspace Mail Review

My Way Mail is a clean, fast and fun (though not particularly advanced) free email service.
It lacks secure messaging and other advanced, non-essential features, though.
My Way Mail Review | My Way Mail Tips