[jolmg]

> Excluding unengaged subscribers who have not opened an email from us in the last XXX days

How would you know if they've opened it? For example, I never allow the display of pictures (external ones, not included in the email itself via data URIs) in my email client, nor anything else that might result in a ping to a server. That's the default behavior of most email clients, isn't it?

[kccqzy]

I used to subscribe to the New Yorker. I do open their newsletters and I do not have images enabled. One day they simply send me an email asking me whether I'm still reading their newsletters, telling me they'll auto-unsubscribe me unless I click a link inside the email within X days.

I find that this is an elegant solution that solves the problem completely; if a user finds your emails valuable enough, they wouldn't hesitate to click a link once every few months to reconfirm their subscription.

[zzo38computer]

I don't know if it is default or not, but it may be a setting. If HTML email is disabled or unimplemented, that would also prevent this tracking.