Knowledge base
Developers
Everything in the app is also a call your own code can make: send mail, scope keys, hear about events, and drive it from a typed client or an agent.
In this section
Email APISend one message or a hundred per call, now or later, and retry without sending twice.API keysA key per job, limited to the scopes and senders it needs, with every call logged.REST APIA documented HTTP API with issuable, scopable, revocable keys.WebhooksTell your endpoint when mail arrives, instead of making you poll.Typed SDKsTypeScript, Python, Ruby, PHP, Go, Java and C# clients, one method for every operation.Command lineYour mailbox and every API operation, from a terminal or a script.MCP serverPoint Claude, or any MCP client, at your mailbox.OAuth for third-party clientsApps register themselves and sign in with PKCE, and you choose the workspace, addresses and permissions each one gets.Move from ResendBring your suppressions, audiences, contacts, templates and webhooks across with one key, with a checklist for your domains and API keys.Move from SendGridPoint the SendGrid SDK at Nextmail and keep your code, then bring lists, suppressions, templates and webhooks across with one key.Move from PostmarkPoint the Postmark client at Nextmail and keep your code, then bring suppressions, templates and webhooks across with one key.Move from MailgunPoint the Mailgun SDK at Nextmail and keep your code, then bring mailing lists, suppressions, templates and webhooks across with one key.Move from MailchimpBring your Mailchimp lists, subscribers and unsubscribes across with one key.Convert your sending codePaste code that sends through Resend, SendGrid, Postmark or Mailgun, and get it back written for Nextmail.Try it in the docsSend a real request from any page of the API reference, with a temporary key that lasts an hour and is scoped to that call.Address checkerWhether an address is worth sending to, before the first message.Events from your appTell Nextmail what a contact did in your product, to start an automation or end a wait.
Google Workspace
Fastmail