Thoughts about electronic mail

I end up talking to students about email more than they or I would like. Here are a few quick notes about ways in which I use (and do not use) email.

Choosing subject lines

I get way too much email, literally hundreds of messages each day. I rely on programs to automatically file my email and to search my email. I also scan email to find high-priority. Hence, I’d appreciate it if you’d help me process email from you more carefully. Here are a few short guidelines.

  • Please take the time to choose an appropriate subject line for your email message.
  • If I tell you to use a particular subject line for an email message, particularly for an assignment, please use that subject line. The correct subject makes it easier for me to file your email and, more importantly, for me to find your email.
  • If you are asking for help on an assignment, please do not use a title like “Homework assignment”. I often assume that titles like that represent submissions of homework assignments, and may file them without looking at them until it comes time to grade the assignment. If you’re asking a question, please put a term like “Question” or “Help” or even “HELP!” in the subject line. (Yes, I know that the use of all capital letters is a form of shouting. It’s okay, and perhaps even preferable, if you virtually shout when asking for help.)
  • If you are replying to a message and are changing the topic of the message, please also change the subject line. If you want to be precise, you can include the old subject line in parentheses, prefixed by the word “Was”, as in “Question on the assignment (was re: This week’s convocation)”.

Reasonable delays

I do my best to respond to email within twenty-four hours. If I do not do so, you should feel free to email me a reminder. If you have an urgent question, please send it via email with “Urgent” (or URGENT) in the title. If I do not respond quickly enough, you can feel free to text me. If you do text me, please include your name. And don’t text without sending email first.

Authentication and encryption

Most of us, myself included, don’t think much about email, other than that it’s a convenient way to communicate. But a few recent events suggest that we should be a bit more thoughtful. Hence, I encourage you to consider using mail encryption software, particularly the GNU Privacy Guard (GPG) and the more general Pretty Good Privacy (PGP) protocol.

Since I use GPG, I’ve written a really brief introduction. There are a host of more useful and more comprehensive introductions to and tutorials about GPG, so I’m not going to write much here, other than to recommend that you learn about using GPG. I will say that, depending on what email package I’m using and who I’m communicating with, encryption is either trivial (one click and one password when I’m using on the Macintosh and sending email) or a slight pain (saving the encrypted message as a file and then running a decryption program when I’m receiving an encrypted message via Webmail).

GPG is available for all three major operating systems (and probably for others, too).

  • On the Mac, I use GPG Suite. I find it simple and straightforward. Most of my colleagues use it too. Unfortunately, GPG Suite has moved from being open-source software to being proprietary software. (At least parts of it have moved.)
  • I don’t use Microsoft Windows, but I hear that gpg4win works pretty well.
  • On the Linux workstations in the MathLAN, GPG is installed as a command line tool.

If you send me your public key (or a link to your public key) and ask me to encrypt email to you, I will do my best to remember (although I may not always succeed). You can find my public key at or at the MIT key server,