Claws Mail

This email client provides basic tools for obtaining fast results when managing your email account.

It offers a variety of features, including GnuPG and SSL support for secure sending, a detailed contact book, spellcheck, filtering, colored labels, and mail processing to help you set your email up exactly how you want it.

If one thing sets Claws Mail apart from other email clients, it's speed, as well as the high level of detail to which you can configure your account.

It's not only a good alternative for a webmail client, but for any conventional email client.