Wandering Thoughts archives

You should segregate different traffic to different mailing lists

In a comment on my entry about how people can always unsubscribe to things, billings wrote:

We actually run a couple mailing lists at work that are set up so you can't unsubscribe, because they are the official communications from the college to staff, students or faculty (each their own list). I argued that we should allow people to unsubscribe if they want, but university policy makes us have to maintain the list for stuff like emergency alerts and official messages from the Dean. [...]

It is my considered opinion that this is a bad idea. Why it's a bad idea is a direct consequence of how people can always unsubscribe and how these two examples are not like each other.

To be blunt, it's quite likely that a lot of people are going to be completely uninterested in official messages from the Dean. If they come out with any frequency, people are going to 'unsubscribe' from them in some way on their client. The more emergency messages resemble the Dean's official messages, the more likely that they too have been quietly 'unsubscribed' from (whether or not the user intended to do this). If you really want people to get emergency messages (and you probably do), this is a very bad thing.

What you want to do here is to differentiate the emergency messages from the Dean's messages as much as possible. The more you differentiate, the less likely that people will miss emergency messages. Because of how people are generally going to do filtering, you want the user-visible message headers to be as different as possible, ie a different From:, a different To: and cc:, a different completely Subject: (with no common prefix), and so on. Since mail clients may at least potentially notice list-related headers when assessing messages, you want to use a different actual mailing list too.

This also applies to less drastic splits in purpose, of course. But don't split too finely, because then you make it too much work for people to unsubscribe from everything they don't want and they start using blunt hammers. To be honest there are only really three categories: lots of people are going to unsubscribe, you hope that only a few people unsubscribe, and you desperately want no one ever to unsubscribe. In an ideal world you'd have very few list splits beyond that (you might want to have a few different purpose-based splits in the middle category).

People can always unsubscribe from your mailing lists

At work, every so often I get added to a mailing list where the people running the list are firmly convinced that it's so important that some or all of the recipients shouldn't be allowed to unsubscribe. There is no gentle way to put it: these people are operating under a tragic and dangerous misconception. The reality is people can always unsubscribe from your mailing lists. The only question is where they do it and if you find out about it.

Specifically, if you don't allow people to unsubscribe at the mailing list level, what inevitably happens is that people silently 'unsubscribe' in their mail client. Any modern mail reading environment offers several different ways of doing this, some of which you will like more than others. Unfortunately the way you will like most (or dislike least) is the one that users are the least likely to use.

The obvious and theoretically best way is to create a filtering rule that junks your mailing list messages (and if you're lucky, is precise enough that it only junks those as opposed to, say, all email that you ever try to send to them). The problem with this is that writing rules is kind of a pain in the ass so in practice the users are likely to use the easier approach, namely clicking whatever 'mark as spam' button their mail client has (it almost certainly has one). After they do this a few times, any competent modern mail client will silently start disappearing your new messages as spam. If you are lucky, this marking only affects mail to that particular user. If you're unlucky, what they're doing is helping to persuade a shared mail provider that your messages should be marked as spam for everyone.

In some modern environments the users don't even have to go this far. If they repeatedly delete your mailing list messages unread or barely read, their mail client is smart enough to learn from this and to start automatically categorizing your email as low-importance. Again, if you're lucky the system did this characterization narrowly enough to just take out the mailing list; if you're unlucky, it will take out more. The good news is that this will probably not reach out to affect other users, although you never know.

So on the whole you're much better off letting people unsubscribe even from mailing lists that you think are really important. At least that way you get to know if your audience agrees with you and you can rethink your efforts if they don't.

(In fact unsubscribes are a really good signal that your efforts are not working. You might say 'but if people unsubscribe we can't get them back with better content'; in practice this is almost certainly a delusion. Once someone has decided that your messages are not worth their time it doesn't really matter how they implement the decision because they're extremely unlikely to pay your future messages enough attention to reconsider it, even if they are just deleting them without any further consequences.)