This article was originally published as part of the Pobox blog. Pobox was acquired by Fastmail in 2015.

Mark Dominus continues his series of articles on how to send email to strangers asking for help. Read the previous entry.

Last week, I told you the one big rule of asking email questions to strangers. This week, I'll discuss a smaller rule:

Use an informative Subject

We all get a lot of junk mail. We all throw away most of it. If the a message doesn't have an eye-catching subject, we may throw it away without opening it. And "eye-catching" here means "does not look like spam". Spammers are very stupid, and they have a very stupid idea of what sort of subjects will be eye-catching:
  • Please reply ASAP
  • Seeking your expertise
  • Help me!
  • READ THIS!!!!!!
You must be cleverer than a spammer. Just adding more exclamation marks is not clever enough. Good subjects in messages I have received and replied to are:
  • Question about apache module
  • Length of day question
  • how to optimize for speed
The key property here is that each subject contains something specific that makes clear what the message is actually about, and that it is something that might reasonably be directed to me, rather than to someone else, or to one million someone elses. Do you remember the important rule from last week? Experts want to be consulted in the area of their expertise. They do not want to be consulted about random garbage. If you can make clear in the subject line that you sought them out for specific knowledge that only they can provide, the expert is much more likely to read your message.

Here the subjects of some messages that I have sent to famous people that have received prompt and detailed replies:
  • Computing with lattices: An application of type classes
  • Hegelian Taco
  • Octopus anatomy
Each of these is good because it instantly tells the recipient two things. First, it tells them what the message will be about. "Hegelian Taco" may not mean anything to you, but it does mean something to the author of the paper about the Hegelian taco that I was asking for. And second, it tells the recipient that the message was intended for them, and for them alone. Anyone else might throw away a message titled "Hegelian taco" in puzzlement, but the author of the Hegelian taco paper is certain to read it, and that's all you care about.

Similarly, the "Computing with lattices" message was sent to the author of a paper with that title, asking for a copy of the paper, and "octopus anatomy" was sent to an octopus expert.

Once you've gotten the recipient to open and read your message, you still have to get them to answer it. I'll return in three weeks with an article about how to keep the expert from throwing away your message in disgust.