Transactional email is one of those infrastructure choices that quietly determines whether 10% or 30% of your emails land in spam. The 2026 landscape: Resend has won DX, Postmark still leads deliverability, SendGrid feels legacy, and a handful of newer players (Loops for marketing, Plunk for self-host) cover edge cases. For most apps, pick Resend or Postmark and move on.
The four worth using
| Service |
Free tier |
Cheapest paid |
Best for |
| Resend |
3,000 emails/mo |
$20/mo (50k) |
Transactional + DX |
| Postmark |
100/mo |
$15/mo (10k) |
Highest deliverability |
| SendGrid |
100/day |
$20/mo (50k) |
Established API |
| Loops |
1k contacts |
$49/mo Pro |
Marketing email |
Best DX — Resend
EDITOR'S PICK
Resend
3,000 emails/month free, $20/mo for 50k, $90/mo for 250k. Built by ex-Vercel team. React Email components for typesafe templates. Best dashboard in the category. Webhook support, broadcast batches, scheduled sends, custom domains.
Visit Resend →
When Resend wins: any modern stack where developer experience matters and your volume is under 1M emails/month.
Best deliverability — Postmark
Postmark has been the deliverability gold standard since 2010. They take spam reports seriously and prune accounts that abuse their network — which is exactly why their senders' inbox rates are highest. The free tier is small (100/mo) but the paid tier at $15/mo for 10k emails is fair.
When Postmark wins: receipts, password resets, anything where a missed email costs real revenue.
When to use SendGrid
Mostly legacy projects already on it. New projects: pick Resend or Postmark instead.
What's NOT worth your money
- Free Gmail / Google Workspace SMTP for production transactional email (rate-limited, deliverability tanks at scale)
- Amazon SES alone without warmup discipline (deliverability suffers vs purpose-built services)
- Mailgun for new projects — has declined since acquisition
- Premium "deliverability monitoring" SaaS — Postmark already does this for free
- Custom SMTP self-host unless you have specific compliance needs (deliverability is hard to maintain solo)
FAQ
What about deliverability — does provider really matter?
Yes, by a lot. Independent tests show Postmark consistently lands 95%+ in inbox; some shared-IP providers drop to 75–85%.
SPF, DKIM, DMARC — do I need to set these up?
Yes, on day one. All four providers walk you through it. Without proper authentication, your emails get marked as spam regardless of provider.
Can I send marketing emails through Resend / Postmark?
Postmark requires marketing email on a separate "Broadcasts" stream. Resend supports broadcasts on Pro tier. For pure marketing email, dedicated tools (Loops, Mailchimp) are usually better.
What about open tracking / click tracking?
All four support it. Privacy-conscious senders sometimes disable open tracking (uses 1px tracking pixel) but keep click tracking.
How do I avoid the spam folder?
Authentication (SPF/DKIM/DMARC), warm sending domain, low bounce rate, low spam complaints, plain-text alternatives, no spammy content. The provider you pick is one factor; sender behavior is the bigger one.
Best for sending 1M+ emails/month?
Resend Pro tier or Postmark Premium. Both scale to millions/month with predictable pricing.
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