DEVELOPER DOCUMENTATION
Build with Mailflow.
Send transactional email from your code with one HTTP request, or over SMTP. Test with an mf_test_ key, then switch to mf_live_ to deliver.
Getting StartedFrom a new project to your first email sent from code.Account and Project SetupOrganize applications and team access.API AuthenticationAuthenticate requests with a project API key.API KeysCreate, restrict and revoke project credentials.Sending DomainsAuthorize Mailflow to send for your domain.Domain Authentication: SPF, DKIM and DMARCThe DNS records that prove mail really comes from you.Domains APIRegister and verify sending domains from code, without the dashboard.Sending Transactional EmailsPOST /api/v1/send: the request, the response and the limits.Batch SendingUp to 1,000 personalised messages in one request.Authenticated SMTPSend through SMTP from an existing application or mail client.Message Status and Email LogsWhat each status means, and how to read it from code.Error CodesEvery error has the same JSON shape and a stable code.Retries and IdempotencyRetry safely without sending twice.TemplatesReuse versioned subjects and content.WebhooksGet told when something happens, instead of polling.Webhook Signature VerificationCheck that a webhook really came from Mailflow.Sandbox EnvironmentExplore requests without real delivery.Usage and Rate LimitsWhat is counted, and how fast you can send.SuppressionsMailflow won't send to addresses that bounced or complained.AnalyticsDelivery trends for the selected project.AutomationsSend emails automatically when someone joins a list or your app reports an event.Contacts, Lists and Signup FormsCollect subscribers with consent, and keep them organised.Broadcast Campaigns · PreviewPlan audience-based mailings.Inbound Email · PreviewPlan inbound domains and routing rules.MCP Integration · PreviewPlan scoped access for compatible AI clients.