Email Providers
Transactional and marketing email APIs for AI-powered applications
| Tool | Type | Pricing | OSS | Transactional | Marketing | Inbound Parsing | Template Engine | Deliverability Tools | Verified |
|---|---|---|---|---|---|---|---|---|---|
| Resend | cloud | Free (100 emails/day)$20/mo ProCustom Enterprise | 2026-04-28 | ||||||
| SendGrid | cloud | Free (100 emails/day)$19.95/mo Essentials$89.95/mo ProCustom Premier | 2026-04-28 | ||||||
| Postmark | cloud | $15/mo (10k emails)$50/mo (50k emails)$100/mo (125k emails)Custom high volume | 2026-04-28 | ||||||
| Mailgun | cloud | Free trial (100 emails/day)$35/mo Foundation$90/mo ScaleCustom Enterprise | 2026-04-28 | ||||||
| AWS SES | cloud | $0.10/1k emailsFree within EC2 (62k/mo)Dedicated IPs from $25/mo | 2026-04-28 |
Supported Not supported Unverified
What do these features mean?
- Transactional — Send triggered emails — receipts, notifications, approval requests
- Marketing — Send bulk campaigns and newsletters
- Inbound Parsing — Receive and parse incoming emails via webhook
- Template Engine — Built-in email template builder or rendering engine
- Deliverability Tools — Dedicated IP, domain authentication, and reputation monitoring
Missing a tool in this category? Use the add-tool skill to generate the file, then open a PR.
Email Providers
AI agents that interact with users often need to send email — notifications, reports, approval requests, summaries, or follow-ups. The email provider you choose affects deliverability, cost, and how cleanly it integrates as an agent tool.
For most agent use cases, you're sending transactional email: a specific message triggered by an agent action, not bulk marketing campaigns. This makes deliverability and API design the two things that matter most.
What to consider:
- API design and SDKs — how easy is it to wrap the email API as a tool in your agent framework? Resend and Postmark have the cleanest modern APIs. SendGrid and Mailgun are more verbose but feature-rich. AWS SES is bare-bones.
- Deliverability — does the email actually reach the inbox? Postmark leads here with dedicated transactional infrastructure. SendGrid and Mailgun have strong deliverability but also serve marketing email, which can affect shared IP reputation.
- Inbound email — if your agent needs to receive and parse emails (not just send), Mailgun's inbound routing is the standout feature. Most other providers are send-only or require separate configuration.
- Cost at scale — AWS SES is the cheapest by far at volume. Resend and Postmark charge per email with no per-seat pricing. SendGrid and Mailgun have tiered plans that can get expensive.
- Templates and rendering — Resend pairs with React Email for building templates in JSX. SendGrid has a visual template builder. Postmark has prebuilt templates for common transactional emails. AWS SES has basic templating only.
If your agent sends fewer than a few thousand emails per month, pick whichever API you find cleanest to work with. At scale, cost and deliverability start to differentiate meaningfully.