YubiKeys are small USB tokens that generate random one time passwords. Together with a PIN they form a two factor authentication passphrase that can be used to login to the mailbox.org web service without compromising the normal password. One time passwords are not reusable. This protects against the risks of keyloggers in public places like Internet cafes.
In addition to secure logins mailbox.org offers the encrypted inbox and a feature rich online office based on Open-Xchange with up to 500GB online drive space."
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