Webmail providers don't provide PGP support because it is not possible to securely implement PGP for webmail. All web-based interfaces are inherently a proxy th

Webmail providers don't provide PGP support because it is not possible to securely implement PGP for webmail. All web-based interfaces are inherently a proxy through a third party, so if you want to read your encrypted mail on the web, you must give your webmail provider the decryption key. Given this, it's better for webmail providers to not pretend to support secure mail.