title: If you send me mail, make it plain

by: Scott Bradner

I do not know why people think I need to see their name in bold when they send me an email message. Or why they think that I'll be impressed if they have a logo on their electronic stationery. Unless someone is sending me a picture I wish that they would stick to plain text email. I've felt this way for a while on general principals but now a number of security problems are strengthening my opinion.

MIME is an annoying standard. The use of IETF Multipurpose Internet Mail Extensions (MIME) email between consenting adults is fine. It is a useful way to send a picture of the family to grandma. But unless the sender knows what software that the receiver uses MIME can be a way to standardize the transmission of gibberish. If you send me a perfectly standards-compliant MIME message containing an AutoCad drawing you have sent me standards-compliant gibberish because I do not have AutoCad support on my machines.

MIME is also a way to standardize the transmission of maximally inefficient messages. It is not all that unusual for me to get a message of more than a million bytes whose useful content is less than 200 characters. The rest is Microsoft Word overhead and fancy stationery complete with multi-color logo and a list of corporate management. It sure is pretty but it is no more informative than just sending the 200 character message by itself. Getting such a message does not put me in a cooperative mood, especially if it just took me 10 minutes to down load it to my desktop in a hotel room. Transmission efficiency is higher if the message is in HTML (the web protocol) but unless you are using a web-based mail reader, which I do not, the message looks like a newspaper that was used to wrap up an order of fish and chips.

So for message size, software compatibility, and message readability reasons I've always asked people to send me plain text email but now there are a growing number of privacy and security reasons to insist on it. MIME transmitted Word files can be full of viruses, executables can destroy your disk, and HTML messages can tell the sender when you open the message and even send a copy back to the sender of any comments you might add when forwarding the message to someone else. None of these problems occur if it’s a plain text message.

Its particularly annoying that many email packages come pre-configured to be in abuse mode and it can be hard to figure out how to tell them to not send pretty messages. Finally, to me it’s a sign of ignorance or arrogance to send non-text messages to mailing lists. The sender is implicitly assuming that all list subscribers use the same software as they do and that they all want to waste down load time.

disclaimer: Ignorance, arrogance and Harvard do not generally go together so the above is my own opinion.