Resend with React Email shipped in 18 minutes, Postmark took 41 minutes plus DMARC tweaks Resend hit 99.7% Gmail placement on 4,212 sends, Postmark hit 99.4% but won Outlook by 2.1 points Postmark dashboard surfaces bounce reasons in one click, Resend hides them two screens deep Postmark costs 13.50€ at 10k sends, Resend costs 18€, gap widens at 50k volume I picked Postmark for production, kept Resend for early-stage projects and React Email previews I run four products from one laptop. Every product sends transactional email: order confirmations, password resets, magic links, weekly digests. For 30 days I split traffic between Resend and Postmark to figure out which one earns the SMTP slot in production. Same templates, same volume, same domain reputation, two different stacks. Here is what 30 days and 8,400 emails actually told me. I went into the test biased toward Resend.…