12-month Development email performance dashboard. 77 campaigns reached 506,601 addresses across Mailchimp and Braze with a weighted-average open rate of 5.7 percent and click rate of 0.35 percent. Volume was concentrated in the OBG 2025 gala (May–June) and EOY 2025 (October–December). Donor and SYBUNT segments outperformed mixed and non-donor lists.

Development email performance — 12-month lookback

77 campaigns · Mailchimp + Braze · April 2025 – May 2026

Audience reached

506,601

total deliveries

Unique clicks

1,793

aggregate engagement

Avg. open rate

5.7%

weighted by audience

Avg. click rate

0.35%

unique clicks ÷ sends

Avg. bounce rate

0.77%

healthy overall

Monthly volume and open rate

Audience reached as bars (left axis), open rate as a line (right axis). The OBG gala in May–June and EOY in Oct–Dec drive most volume.

Audience reached Open rate (weighted)
Monthly volume peaks at 180K addresses in June 2025 with the OBG gala. Open rate is highest in November 2025 at 14.7 percent and lowest in August 2025 at 2.3 percent.

Engagement by audience segment

Open rate scales with prior relationship. SYBUNT (lapsed donors) and Donors lead; Non-Donor cold lists trail.

OB Staff 32.4%, SYBUNT lapsed 13.6%, Donors 8.1%, Alumni 6.2%, Mixed 5.8%, Caregivers 5.1%, Non-Donors 2.4%.

Top campaign groups by reach

Two clusters dominate the year: the OBG 2025 gala and the 2024 Impact Report.

OBG 2025 Gala 253,893; Impact Report 2024 72,671; EOY 2025 67,480; Lilly Foundation 36,684; Reset Summit Fund 28,639; Spring Caregiver Appeal 9,325; Donor Benefits 7,026; Spring Appeal 2026 6,622; CBOBS YEC 4,498; Grateful for You 4,437.

Two outliers worth a deliverability review

SPRING CAREGIVER APPEAL — GMAIL SPLIT

Same campaign, sent a day apart in Braze. Primary send: 46.2% open on 2,850 addresses. Gmail variant: 0.7% open on 3,879. Likely Gmail placement issue — content scoring or sender reputation.

NH INTRO — BOUNCE RATE

DEV: NH Intro to Existing Donors (Group B), 5/27/25 — 6.8% bounce on 1,985 addresses. NWOBS Donor Retention earlier that month: 2.9%. NH and NWOBS donor lists need a hygiene pass before the next direct send.

Open-rate read across platforms

Mailchimp suppresses Apple MPP auto-opens; Braze does not. Same-campaign opens look very different across platforms because of methodology, not list quality. The cleanest cross-platform comparison is click rate and bounce rate — use those when reporting blended figures, and footnote any aggregate open rate.