InstAddr - Disposable email address application.
Inbox.lv - Inbox.lv Mail
Horde - Horde Groupware is a free, enterprise ready, browser based collaboration suite.
CounterMail - Countermail is a web-based email service. It is hosted in Sweden. Its focus is on privacy.
Mailo - Mailo is an email client where you can send and receive emails to and from anyone with an email address.
Yaani Mail - E-Mail Service, Mobile Application, Web