1. Installation Add the SDK to your project using Maven or Gradle:
< dependency > < groupId > co.lettermint </ groupId > < artifactId > lettermint </ artifactId > < version > LATEST </ version > </ dependency >
2. Send your first email Initialize the client with your API token:
import co.lettermint.Lettermint; Lettermint lettermint = new Lettermint ( "your-api-key" );
Send your first email:
SendEmailResponse response = lettermint . email () . from ( "John Doe <john@yourdomain.com>" ) . to ( "recipient@example.com" ) . subject ( "Hello from Lettermint!" ) . text ( "Hello! This is a test email." ) . send (); System . out . println ( "Email sent with ID: " + response . getMessageId ());
3. Email Features Basic Email Send a simple text or HTML email:
lettermint . email () . from ( "John Doe <john@yourdomain.com>" ) . to ( "recipient@example.com" ) . subject ( "Your account is ready!" ) . html ( "<h1>Welcome!</h1><p>Thanks for signing up.</p>" ) . text ( "Welcome! Thanks for signing up." ) . send ();
Multiple Recipients Send to multiple recipients using CC and BCC:
lettermint . email () . from ( "John Doe <john@yourdomain.com>" ) . to ( "user1@example.com" , "user2@example.com" ) . cc ( "manager@yourdomain.com" ) . bcc ( "archive@yourdomain.com" ) . subject ( "Monthly Newsletter" ) . html ( "<h1>This Month's Updates</h1>" ) . send ();
Custom Headers and Reply-To Add custom headers and set reply-to addresses:
import java.util.Map; lettermint . email () . from ( "support@yourdomain.com" ) . to ( "customer@example.com" ) . replyTo ( "help@yourdomain.com" ) . subject ( "Support Ticket #12345" ) . headers ( Map . of ( "X-Priority" , "1" , "X-Ticket-ID" , "12345" )) . html ( "<p>Your support ticket has been updated.</p>" ) . send ();
Add metadata for tracking and webhook payloads:
import java.util.Map; lettermint . email () . from ( "notifications@yourdomain.com" ) . to ( "user@example.com" ) . subject ( "Order Confirmation" ) . metadata ( Map . of ( "order_id" , "12345" , "customer_id" , "cust_789" , "campaign" , "order_confirmation" )) . html ( "<p>Your order has been confirmed.</p>" ) . send ();
Metadata is included in webhook payloads but not added to the actual email headers. Use it for tracking and analytics purposes.
Categorize emails for filtering and analytics:
lettermint . email () . from ( "alerts@yourdomain.com" ) . to ( "admin@example.com" ) . subject ( "System Alert" ) . tag ( "system-alerts" ) . html ( "<p>Critical system alert detected.</p>" ) . send ();
One tag per message. Tags can contain letters, numbers, hyphens, underscores, and spaces (max 255 characters).
See Tags documentation for more details. Route Selection Direct emails to specific routes within your project:
lettermint . email () . from ( "notifications@yourdomain.com" ) . to ( "user@example.com" ) . subject ( "Welcome!" ) . route ( "transactional" ) . html ( "<p>Welcome to our platform.</p>" ) . send ();
File Attachments Attach files to your emails:
import java.nio.file.Files; import java.nio.file.Path; import java.util.Base64; // Read file content byte [] fileContent = Files . readAllBytes ( Path . of ( "/path/to/document.pdf" )); String encodedContent = Base64 . getEncoder (). encodeToString (fileContent); lettermint . email () . from ( "invoices@yourdomain.com" ) . to ( "customer@example.com" ) . subject ( "Your Invoice" ) . html ( "<p>Please find your invoice attached.</p>" ) . attach ( "invoice.pdf" , encodedContent) . send ();
4. Response SendEmailResponse response = lettermint . email () . from ( "John Doe <john@yourdomain.com>" ) . to ( "recipient@example.com" ) . subject ( "Test" ) . text ( "Hello!" ) . send (); System . out . println ( response . getMessageId ()); // Email ID System . out . println ( response . getStatus ()); // Current status
Next Steps
Tags Organize and filter emails with tags.
Tracking Track opens, clicks, and deliverability.
Webhooks Receive real-time delivery notifications.
SMTP Alternative Send via SMTP instead of the API.
GitHub Repository Find the complete source code, report issues, or contribute on GitHub.
