> ## Documentation Index > Fetch the complete documentation index at: https://docs.autosend.com/llms.txt > Use this file to discover all available pages before exploring further. # How to send emails from Supabase with SMTP > Configure Supabase Auth to send authentication emails through AutoSend SMTP. export const APP_PATHS = { home: '/', quickstart: '/quickstart', domainConfiguration: '/domain', apiReference: '/api-reference', sendEmail: '/api-reference/mails/send', bulkSendEmail: '/api-reference/mails/bulk', upsertContactApiRef: '/api-reference/contacts/upsert-contact', transactional: '/transactional-emails', emailActivity: '/transactional-emails/email-activity', emailTemplates: '/transactional-emails/email-templates', sendingEmail: '/quickstart/email-using-api', transactionalTroubleshooting: '/transactional-emails/troubleshooting', marketing: '/marketing-emails', campaigns: '/marketing-emails/campaigns', contacts: '/marketing-emails/contacts', contactsIntroduction: '/marketing-emails/contacts/introduction', contactsImportCsv: '/marketing-emails/contacts/import-csv', contactsLists: '/marketing-emails/contacts/lists', contactsSegments: '/marketing-emails/contacts/segments', contactsCustomFields: '/marketing-emails/contacts/contact-properties', contactsContactProperties: '/marketing-emails/contacts/contact-properties', createContactPropertyApiRef: '/api-reference/contact-properties/create', listContactPropertiesApiRef: '/api-reference/contact-properties/list', getContactPropertyApiRef: '/api-reference/contact-properties/get-by-name', deleteContactPropertyApiRef: '/api-reference/contact-properties/delete', sender: '/marketing-emails/sender', unsubscribeGroups: '/others/unsubscribe-groups', webhookIntroduction: '/others/webhooks/introduction', webhookEventType: '/others/webhooks/event-type', webhookRetries: '/others/webhooks/retries', webhookVerifyRequests: '/others/webhooks/verify-requests', dynamicTemplates: '/dynamic-templates', guides: '/guides', sitemap: '/sitemap.xml', team: '/others/team', automations: '/automations', events: '/automations/events', sendEventApi: '/api-reference/events/send-event', smtpIntroduction: '/quickstart/smtp', betterAuth: '/guides/better-auth', convexGuide: '/guides/convex', templateVariables: '/transactional-emails/variables', suppressions: '/others/suppressions', rateLimit: '/api-reference/rate-limit', nodejsSdk: '/sdk/nodejs', smtpIntegrationGuides: '/guides/smtp', apiKeys: '/api-keys', encryptedPayloads: '/others/encrypted-payloads', apiReferenceIntroduction: '/api-reference/introduction', lovableGuide: '/ai/integrations/lovable', aiIntroduction: '/ai/introduction', aiSkills: '/ai/skills', aiMcpServer: '/ai/mcp-server', aiLovable: '/ai/integrations/lovable', aiBolt: '/ai/integrations/bolt', aiV0: '/ai/integrations/v0', aiReplit: '/ai/integrations/replit', mcpClaude: '/ai/mcp-clients/claude', mcpCursor: '/ai/mcp-clients/cursor', mcpCopilot: '/ai/mcp-clients/copilot', mcpWindsurf: '/ai/mcp-clients/windsurf', mcpCodex: '/ai/mcp-clients/codex', mcpAntigravity: '/ai/mcp-clients/antigravity', mcpChatgpt: '/ai/mcp-clients/chatgpt', mcpRaycast: '/ai/mcp-clients/raycast', domainWarmup: '/marketing-emails/domain-warmup', projects: '/projects', createAutomationApi: '/api-reference/automations/create-automation', migrationSendgrid: '/migration/sendgrid', migrationResend: '/migration/resend', auth0CustomAction: '/guides/auth0-custom-action', accountBilling: '/others/account/billing', accountUsage: '/others/account/usage', inboundIntroduction: '/inbound/introduction', listInboundMessagesApi: '/api-reference/inbound-emails/list-messages', getInboundMessageApi: '/api-reference/inbound-emails/get-message', downloadInboundAttachmentApi: '/api-reference/inbound-emails/download-attachment', replyToInboundMessageApi: '/api-reference/inbound-emails/reply-to-message', wikiDailySendingLimit: '/wiki/daily-sending-limit' }; export const AUTOSEND_PATHS = { dashboard: 'https://autosend.com/dashboard', apiKey: 'https://autosend.com/account/api-key', faqs: 'https://autosend.com/faq', marketingEmails: 'https://autosend.com/marketing-emails', webhooks: 'https://autosend.com/webhooks', composeByAutoSend: 'https://autosend.com/compose', emailActivity: 'https://autosend.com/email-activities', team: 'https://autosend.com/settings/team', pricing: 'https://autosend.com/pricing', verifyEmail: 'https://autosend.com/compose/email-builder?template=verify-email', welcomeEmail: 'https://autosend.com/compose/email-builder?template=welcome-email', productUpdate: 'https://autosend.com/compose/email-builder?template=product-update', newsletter: 'https://autosend.com/compose/email-builder?template=newsletter', automations: 'https://autosend.com/automations', globalSuppressions: 'https://autosend.com/suppressions/global', signup: 'https://autosend.com/signup', domains: 'https://autosend.com/settings/domains', smtpKey: 'https://autosend.com/settings/smtp', logoKit: 'https://asend.email/logo', contactsPage: 'https://autosend.com/contacts/list-and-segments', accountBilling: 'https://autosend.com/account/billing', accountUsage: 'https://autosend.com/account/usage', terms: 'https://autosend.com/legal/terms', inbound: 'https://autosend.com/email-activities/inbound' }; AutoSend x Supabase Supabase uses email for authentication flows like sign-up confirmations, password resets, and magic links. By default, Supabase uses its built-in email provider, but it has rate limit. For production apps, you can configure it to use AutoSend SMTP for better deliverability. ## Prerequisites Make sure you have a verified domain added in AutoSend to send emails from. Create a project-specific SMTP key from the SMTP tab in Project Settings. ## Configuration 1. Go to your [Supabase dashboard](https://supabase.com/dashboard) 2. Select your project 3. Navigate to **Authentication** 4. Under Notifications, you will see **Email** Section. 5. Go to **SMTP Settings** tab. Supabase Step 1 Toggle **Enable Custom SMTP** to enable the SMTP configuration form. Supabase Step 2 Fill in the following settings: | Field | Value | | ---------------- | ---------------------------------------------------------- | | **Sender email** | `noreply@yourdomain.com` (must match your verified domain) | | **Sender name** | Your app name (e.g., "MyApp") | | **Host** | `smtp.autosend.com` | | **Port number** | `587` | | **Username** | autosend | | **Password** | Your AutoSend SMTP key (AS\_xxx) | The SMTP password is no longer your API key. Create a project-specific SMTP key from the SMTP tab in Project Settings. Supabase Step 3 Click **Save** to apply your SMTP configuration. Send a test email to verify your configuration: 1. Go to **Authentication** → **Users** 2. Click **Invite user** 3. Enter a test email address 4. Click **Invite** Check the recipient's inbox to confirm the email was delivered through AutoSend. ## Email Templates Supabase allows you to customize the email templates used for authentication. You can modify these in **Authentication** → **Email Templates**. Available templates: * **Confirm signup** - Sent when a user signs up * **Invite user** - Sent when inviting a user to your project * **Magic link** - Sent for passwordless login * **Change email address** - Sent when a user requests an email change * **Reset password** - Sent for password recovery Supabase email templates use Go templating syntax. Variables like `{{ .ConfirmationURL }}` are replaced with actual values when the email is sent. ### Example Custom Template Here's an example of a customized signup confirmation template: ```html theme={null}

Welcome to MyApp!

Thanks for signing up. Please confirm your email address by clicking the button below:

Confirm Email

If you didn't create an account, you can safely ignore this email.

Thanks,
The MyApp Team

``` ## Rate Limits Supabase applies rate limits to authentication emails to prevent abuse. These limits are: * **30 emails per hour** per user * **4 emails per hour** for the same action (e.g., password reset) AutoSend's rate limits are separate and typically higher. Check your plan limits for details. ## Troubleshooting * Verify your SMTP credentials are correct - Check that your sender email domain is verified in AutoSend - Ensure the sender email matches a verified domain - Check Supabase logs for SMTP connection errors * Ensure your domain has proper DNS records (SPF, DKIM, DMARC) - Use a professional sender name, not "noreply" - Avoid spam trigger words in your email templates - Check your domain reputation in AutoSend * Supabase may have firewall restrictions on certain IP ranges - Try using port 465 instead of 587 - Contact Supabase support if the issue persists * Double-check your SMTP key is correct - Ensure the username is `autosend` and the password is your SMTP key - Verify your SMTP key is active in the SMTP Settings ## Alternative: Supabase Edge Functions For more advanced use cases, you can use Supabase Edge Functions with the AutoSend API instead of SMTP. This gives you access to features like: * Email templates with dynamic variables * Detailed delivery tracking * Webhook notifications Learn how to send emails from Supabase Edge Functions using the AutoSend API