Smtp is a plain text protocol . What does that mean? It means the actual emails you send are about as private as a postcard. The sender, the recipient, and the message itself are all plainly visible to anyone who comes in contact with it. Chances are that your letter carrier and the the folks at the post office don’t care about what you wrote on your post card, and are too busy to bother reading it. Likewise, most of your neighbors are not snooping about when you drop your postcard in the mail box or when the letter carrier picks it up. Still, i wouldn’t write anything in an email, that i wouldn’t write on a postcard.
Further Reading
E-mail – Wikipedia article
How Email Works – HSW article
RFC 822 – The technical standard
Where are the people who might read it? How do they see it?
Example 1: You send an email from your Hotmail account to your friend’s Yahoo account. The server administrators at Hotmail can see your email, and so can the admins at Yahoo. I’m sure they have more important things to do than read random emails, but the point is that they can if they want to.
Example 2: You send an email from your account with Comcast, Cox, Qwest, etc., to your friend’s email account at their work. The server administrators at Comcast, Cox, Qwest, etc., and the admins at your friend’s work can see the email if they want to.
Example 3: You’re sending email from a computer using a wireless connection at home or the coffee shop. This scenario gets a little complex, but it is completely plausible that a technically savvy nosy neighbor or coffee shop patron will be able to see your email as it flies through the air from your computer to the wireless access point.
Conclusion: More often than not, your email will only be read by the person(s) you sent it to, but still, i wouldn’t write anything in an email that i felt was too sensitive to be written on a postcard.
Don’t forget the U.S. (and other) government(s). They have the technical means to scan any electronic communication for key words and phrases. If you happen to use one of these, what happens? Do you wind up on the “Do not fly” list? We don’t know.
Use encryption, and use secure email servers such as Novo Ordo’s (http://www.novo-ordo.com).
Excellent points. I think i will continue this discussion in a follow up post. (Email Privacy Continued) Incidentally, i have never used Novo Ordo’s service, but after glancing over a few pages on their site, i can tell you the info is accurate.