Marketing Tech
The Deliverability Black Box: SendGrid vs. Resend
Feb 20, 2026 7 min read
Your transactional emails (Magic Links, Password Resets) are the lifeblood of your SaaS. If they hit spam, you lose users.
The old king, SendGrid, has a reputation problem. Shared IPs are often blacklisted. The new challenger, Resend (built on AWS SES), promises better DX and deliverability. We tested both.
Vertex Summary (TL;DR)
- Inbox Placement: Resend hit the Primary Inbox 98.5% of the time. SendGrid (Free Tier) hit it 82% of the time.
- Speed: Resend delivered emails in <1.5s on average. SendGrid took >4s (often delayed by queues).
The "Shared IP" Trap
When you use SendGrid's free or lower-tier plans, you share an IP address with thousands of other developers. If one of them spams, you get punished by Gmail's filters.
Resend seems to curate their IP pools much more aggressively, or they are utilizing AWS SES's high-reputation infrastructure more effectively.
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