43 Folders has five fast e-mail productivity tips, and I think it’s a fine list. However, if you have more time and an interested group of people, I offer this suggestion: subject codes. In my organization, nearly every e-mail that’s sent has one of the following subject codes in the title:

AR: action required, the e-mail requires you to take some action
FYI: for your information, this e-mail is for your information, no action required
PYR: per your request, the e-mail contains information you’ve requested
Q: question, there’s a question for you in the e-mail
EOM: end of message, for those willing to put the entire message in the subject line

We had heavy buy-in from senior management, so there was an especially high uptake when we introduced them. However, people are still using subject codes three year later — a good sign that it’s meeting needs. It also helps that most of us have the codes in our signature files.

We didn’t invent this, but I can’t remember where we judiciously swiped the idea.