Guides
Email API guides
Each guide is a working integration for one stack — where to put the API key, how to call the send endpoint, and what to do when it fails. For the client's full surface (every option, every method, the typed errors), read the Node SDK reference instead — these guides link to it rather than repeating it.
Framework guides
Next.js
Send from a Server Action and from a Route Handler, with the API key kept server-side where it belongs.
Node.js & Express
A POST route that sends a welcome email, with the error handling and retry rules that keep it from misbehaving under load.
React Email
Write your template as a React component and pass it straight to the SDK — no manual render step.
Convex
Send from a Convex action, and why the send belongs there rather than in a mutation.
Deliverability
Getting the mail sent is the easy half. These cover the half that decides whether it arrives — and most of them apply whichever provider you use.
SPF, DKIM & DMARC
What each record actually proves, why alignment is the part that decides whether DMARC passes, and how to check what the world can see.
Bounces & suppression
Hard versus soft bounces, why a suppression list is not optional, and how to import one before your first send when migrating provider.
One-click unsubscribe
The two headers RFC 8058 needs, why acting on a GET quietly unsubscribes your best customers, and how bulk-scoped suppression spares password resets.
Gmail & Yahoo requirements
The bulk sender rules in practice: aligned authentication, one-click unsubscribe, and a spam complaint rate you cannot directly observe.
AWS SES sandbox
What the sandbox restricts, what to write in the production access request, and the three reasons requests come back refused.
AWS SES bounce rate
The thresholds, what review and pause actually mean, and the simulator addresses that let you test a bounce without damaging your own account.
Related reading
Two questions arrive alongside deliverability often enough to belong here: where the mail is sent from, and how this compares with whatever you are using now.
- UK sending — Where mail is dispatched from, what is and is not claimed about data residency, and the retention, export and deletion controls behind it.
- UK vs EU data residency — Why an EU region is not automatically a UK answer, and why eu-west-2 is London despite the prefix. Read this before answering a residency question on a vendor form.
- Comparisons — How this compares with AWS SES, Resend, Postmark and SendGrid — each naming what the other product is genuinely better at.