Make your e-mail disappear

Are you haunted by some of the things you’ve said in e-mail over the years? You can’t change the past, but an add-on to Microsoft Outlook will let you render your e-mail unreadable after a specified time.

Disappearing Email is developed by Disappearing Inc., which already offers a version for corporations. That product lets system managers set e-mail policies and includes several sophisticated features, according to the company.

The free edition for Outlook, which is currently available, focuses on simplicity. When you download the Disappearing Email for Microsoft Outlook plug-in (about 350KB) from Disappearing’s Web site, 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 e-mail can be read by any mail client that handles HTML, including all major e-mail programs and browser-based e-mail, such as Hotmail or Yahoo. When the recipient opens the e-mail, 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 recently, 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.”