The summer reengagement playbook

Summer is just around the corner.

And the list you cultivate this summer is the list you’ll fundraise on in December.

Right now, it might be carrying months of dead weight: subscribers who stopped opening, or contacts who bounced quietly.

By fall, you won’t have time to deal with it. So take advantage of summer slowdowns to deal with it now.

The cost of waiting
M+R’s 2026 Benchmarks report found that 4% of email subscribers became unreachable due to bounces in 2025, and another 12% unsubscribed.

If your list is full of subscribers who haven’t opened an email in six months, you’re dragging down deliverability and diluting the metrics that would tell you what’s actually working.

What a solid summer reengagement push looks like
All you need is a sequence and a deadline.

Defenders of Wildlife built a dynamic segmentation model that prioritized engaged users and gradually expanded outward.

Their active send audience grew from 180,000 to 425,000.

Open rates climbed from the 35–40% range to 45–50%. Their sender reputation hit a 90 send score in Validity.

Equimundo took a different path. They cut their send list by 50%, built dynamic engagement segments, and focused on a single call to action per email.

The smaller list drove 31% more clicks.

How to use the next 8 weeks
Run your reengagement series now, not in October. Identify subscribers who haven’t opened or clicked in 6–12 months. 

Send a short series of 2-3 emails that give them a reason to stay or a clear path to opt out.

Suppress what needs suppressing. If someone doesn’t respond to your reengagement series, let them go.

A smaller list with better engagement will raise more money in December than a big list with poor deliverability.

But I also know that conversation with leadership can be uncomfortable. Frame it around revenue and long-term list health, not size.

Rebuild your segments before fall. Who opened in the last 90 days? Who clicked but didn’t give? Who gave once and went quiet?

Build those audiences now so you’re not scrambling to create them while also drafting your Giving Tuesday emails.

Re-introduce reactivated subscribers. One more thing from the Benchmarks worth flagging: welcome series emails had a 1.6% click-through rate in 2025, nearly three times that of standard fundraising emails.

If you reactivate lapsed subscribers this summer, don’t just dump them back into your regular sends. Run them through a re-introduction sequence first.

They’re basically new subscribers at this point. Treat them like it!

The bottom line
A strong December starts with the boring but essential work you do in July. 

Clean the list, build the segments, give yourself a head start before year-end chaos kicks in.

Check our events list for more or reply to this email to submit one for consideration.

‘Til next time!
Sara