What You Can Build with Lettr
Transactional Emails
Password resets, order confirmations, shipping notifications, account alerts, and any email triggered by user actions.
Marketing Campaigns
Newsletters, announcements, and promotional emails with open and click tracking.
Inbound Processing
Receive and parse incoming emails to power support tickets, reply detection, and automated workflows.
Email Automation
Build complex email flows with webhooks, templates, and real-time event tracking.
Core Capabilities
Lettr provides everything you need for production email infrastructure:Send at Scale
Send at Scale
Send individual emails or batch thousands with a single API call. Lettr handles queuing, delivery optimization, and retry logic automatically. Support for HTML, plain text, and AMP email formats with automatic MIME handling.
Domain Authentication
Domain Authentication
Configure SPF, DKIM, and DMARC records through the dashboard or API. Lettr guides you through DNS setup and verifies your configuration to ensure maximum deliverability. Support for multiple sending domains, tracking domains, and custom storage domains for email assets.
Real-Time Tracking
Real-Time Tracking
Track opens, clicks, bounces, spam complaints, and unsubscribes as they happen. Receive instant webhook notifications or query the API for detailed analytics. Custom tracking domains keep your brand visible in every link.
Template System
Template System
Create email templates with the visual Topol.io editor or write HTML directly. Use variables for personalization and store templates in Lettr for consistent branding across your application.
Suppression Management
Suppression Management
Automatic handling of bounces, spam complaints, and unsubscribes protects your sender reputation. Lettr maintains suppression lists and prevents sending to problematic addresses without any code on your part.
Inbound Email
Inbound Email
Receive emails at your domain and process them programmatically. Parse sender information, subject, body, and attachments via webhooks. Build support inboxes, reply detection, or any workflow that starts with an incoming email.
Get Started
Choose your integration path and send your first email:Laravel
Official SDK with interactive setup
PHP
Get started with Lettr using PHP
Node.js
Get started with Lettr using Node.js
SMTP
Connect via SMTP protocol
How It Works
Get Your API Key
Create an account at app.lettr.com and generate an API key from your dashboard. Keys can be scoped to sending-only or full access.
Verify Your Domain
Add your sending domain and configure DNS records for SPF, DKIM, and DMARC authentication. Lettr provides the exact records to add and verifies your setup.
Send Your First Email
Make a single API call to send an email. Lettr handles delivery, tracking, and bounce processing automatically.
Why Lettr?
Developer-First Experience
Developer-First Experience
Clean REST APIs with predictable responses, comprehensive SDKs for popular languages, and documentation written by developers for developers. No enterprise sales calls required—sign up and start building.
High Deliverability
High Deliverability
Lettr maintains relationships with major email providers and continuously optimizes delivery infrastructure. Automatic warm-up for new domains, reputation monitoring, and feedback loop integration help ensure your emails reach the inbox.
Real-Time Visibility
Real-Time Visibility
Know exactly what’s happening with every email. Track delivery status, opens, clicks, and bounces as they occur. Webhooks deliver events in real-time, and the dashboard provides at-a-glance analytics.
Flexible Integration
Flexible Integration
Use the REST API directly, integrate with official SDKs, or connect via standard SMTP. Lettr fits into your existing stack without requiring architectural changes. Works with serverless functions, traditional servers, and everything in between.