Re-engagement emails are a great tool for fixing deliverability problems like spam traps, abandoned inboxes, and mail stuck in spam, especially at big consumer ISPs.
Laura at WttW has put together an excellent breakdown.
https://www.wordtothewise.com/2025/12/lets-talk-reengagement/

Let's Talk Reengagement
I appear to have written a lot about about re-engagement on the Email Geeks slack channel the last few days. The problem with slack is it’s not great at archiving or keeping information in an accessible, searchable manner. So, I’ve pulled together the answers, rearranged it, made it slightly more coherent and a little less stream of consciousness, so I can reference this when the topic comes up again.


