The shortlist
Three teachers. One model.
HubSpot is the campaign teacher. Klaviyo is the suppression teacher. SendGrid is the after-send teacher.
| Role | Customers | Reviews | For Perch | |
|---|---|---|---|---|
| 1 | HubSpot | 306,446 platform customers. Email is a module. | G2 4.4 from ~15k. Gartner B2B MAP Leader, sixth year. | Best match: B2B mail on people and companies. |
| 2 | Klaviyo | 193,000+ paying. $1.23B FY2025. | G2 4.6. First-year Gartner Challenger. | Retail data. Steal hard-bounce lock. |
| 3 | Twilio SendGrid | 45,000 paying. 2.4 trillion emails in 2025. | G2 Email API ~4.0. Weak support scores. | Steal webhooks, bounce classes, per-yard isolation. |
What we take
Copy the ideas. Keep our pipe.
- One-click unsubscribe. RFC 8058 headers on campaign MIME, plus the footer link we already render.
- Wider suppression. Hard bounce, spam complaint, and one-click POST join today’s opt-out list. A hard bounce stays suppressed.
- Stream split. Campaign From stays off the human mailbox From. Perch already forbids reuse of mailbox compose.
- Delivery events. Record delivered, bounce, drop, and complaint on the send row. Skip open and click as success.
- CRM fields in the letter. Personalize from the live person, yard, and job record, the way HubSpot uses contact and company fields.
Leave HubSpot as a vendor, contact-tier billing, template galleries, and any second sender. Campaigns stay on perch_native.
Sources
Where the numbers come from
| Claim | Source |
|---|---|
| HubSpot G2 4.4 | G2 Marketing Hub |
| HubSpot PCMag 4.5 | PCMag, 26 Jun 2026 |
| Gartner Leader, sixth year | HubSpot 2026 B2B MAP reprint |
| 306,446 customers | HubSpot Q2 2026 EX-99.1 |
| Klaviyo 193,000+ | Klaviyo 10-K, 31 Dec 2025 |
| SendGrid 2.4 trillion | Twilio SendGrid compare |
| Google sender rules | Gmail sender guidelines · RFC 8058 |
Back
ESP Recommendations
The two-minute brief
Why HubSpot is the study model, and why the others fell short.