[pwg]

> Then last Wednesday, it dropped to low 30's. Our format hasn't changed, our content hasn't changed. Mailchimp doesn't see anything wrong. We can't figure out what might have caused the drop.

A fairly significant number of recipients disabling tracking/opening detection on the client end?

In my case, I have never allowed an email sender to have any knowledge of whether I have ever opened an email they send. Maybe more people are turning off the tracking?