Disappearing Email is developed by Disappearing Inc., which already offers a version for corporations. That product lets system managers set email policies and includes several sophisticated features.
The free edition for Outlook, which becomes available this week, focuses on simplicity. When you download the Disappearing Email for Microsoft Outlook plug-in (about 350KB) from Disappearing's website, it's automatically installed and a "Send Disappearing" icon appears on the Outlook toolbar. (The plug-in doesn't currently work with Outlook Express.)You use Outlook in the normal way to compose messages. If you want to set a time limit on the message, you click the Send Disappearing icon. The plug-in encrypts your messages using the 128-bit Blowfish algorithm. It accesses Disappearing's key server through a secure link, assigns a unique decryption key, and sends the message on its way. (A drop-down menu lets you set a time limit for the message, but the default is 45 days.)The simplicity of the system is underscored on the receiving side. The recipient doesn't need a plug-in or any special software to read your message. Your mail can be read by any mail client that handles HTML, including all major email programs and browser-based email such as Hotmail or Yahoo. When the recipient opens the email, the message retrieves the decryption key from Disappearing's key server and it's displayed in decrypted form.
But after the time limit specified by the sender, the decryption key is erased from Disappearing's key server, making the message unreadable and effectively destroying it, even if the recipient stored it.
Unlike some other mail encryption utilities such as SigabaSecure, introduced last week, Disappearing Email doesn't attempt to authenticate the recipient's identity.
This leaves the onus on the sender to make sure the message isn't sent to the "wrong" people. Anyone who receives it can read it during its allotted life. But that's not the program's primary function, according to Maclen Marvit, Disappearing's chief executive officer. Rather, Disappearing Email for Microsoft Outlook is designed to solve what he terms one of the biggest problems of electronic communications: "messages hanging around."
The free version of Disappearing Email doesn't offer some of the more sophisticated features of the corporate version. The free version can't call back a message before it's read, or track when messages have been read.
Company representatives say they're working on a Disappearing plug-in for Lotus Notes, and expect to soon release free plug-ins for other popular email programs, such as Outlook Express and Eudora.