Any tips on how to trigger the people in the database who did not @engage with us last 90 days so they start interacting again? What kind of content would work the best?
You can use a combination of "Not" filters (Not has clicked, not has filled out form, ...)
If you use scoring and do not set negative score for inactivity, you can also use a "not score was changed"
There are some threads on this.
Retrieving data ...