Overview
SendGrid and Postmark are both premium transactional email services, but with fundamentally different philosophies. SendGrid (owned by Twilio) is an enterprise platform that handles everything - transactional, marketing, at massive scale. Postmark is laser-focused on one thing: delivering transactional emails as fast and reliably as possible.
The Philosophy Difference
Postmark is so focused on transactional deliverability that they don't allow bulk marketing email at all. They believe mixing marketing with transactional hurts deliverability for the emails that matter most - password resets, receipts, notifications. SendGrid takes the opposite approach: one platform for all email types.
Delivery Speed
Postmark's transactional delivery is industry-leading. They publish their delivery metrics publicly and guarantee speed. Password reset emails arrive in seconds. For time-sensitive transactional emails, Postmark is the premium choice.
SendGrid is fast too, but it's not their sole focus. At enterprise scale with dedicated IPs, you can achieve excellent deliverability, but it requires more management.
Scale and Flexibility
SendGrid handles enterprise volumes - billions of emails monthly. You get dedicated IPs, subuser management, advanced analytics, and full infrastructure customization. For massive scale with complex needs, SendGrid is better equipped.
Marketing Email
If you need marketing email too, SendGrid has a full marketing platform built-in. Postmark offers "Broadcast" for newsletters but keeps it strictly separate from transactional. You're managing two streams instead of one.
Making the Choice
For critical transactional emails where speed and deliverability are paramount, Postmark is the premium choice. For enterprise scale, marketing needs, or wanting everything in one platform, SendGrid offers more flexibility.