Use base32 encoded UUID to reduce address size

README.md

@@ -108,9 +108,9 @@ You'll obtain the best results with a custom [transport rule](https://www.postfi
 
   ```
   # Transport map - route test emails to happyDeliver LMTP server
-  # Pattern: test-<uuid>@yourdomain.com -> LMTP on localhost:2525
+  # Pattern: test-<base32-uuid>@yourdomain.com -> LMTP on localhost:2525
 
-  /^test-[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}@yourdomain\.com$/  lmtp:inet:127.0.0.1:2525
+  /^test-[a-zA-Z2-7-]{26,30}@yourdomain\.com$/  lmtp:inet:127.0.0.1:2525
   ```
 
 3. Append the created file to `transport_maps` in your `main.cf`:
@@ -144,7 +144,7 @@ Response:
 ```json
 {
   "id": "550e8400-e29b-41d4-a716-446655440000",
-  "email": "test-550e8400@localhost",
+  "email": "test-kfauqaao-ukj2if3n-fgrfkiafaa@localhost",
   "status": "pending",
   "message": "Send your test email to the address above"
 }

docker/postfix/transport_maps

@@ -1,4 +1,4 @@
 # Transport map - route test emails to happyDeliver LMTP server
-# Pattern: test-<uuid>@domain.com -> LMTP on localhost:2525
+# Pattern: test-<base32-uuid>@domain.com -> LMTP on localhost:2525
 
-/^test-[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}@.*$/  lmtp:inet:127.0.0.1:2525
+/^test-[a-zA-Z2-7-]{26,30}@.*$/  lmtp:inet:127.0.0.1:2525

internal/api/handlers.go

@@ -22,8 +22,10 @@
 package api
 
 import (
+	"encoding/base32"
 	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/gin-gonic/gin"
@@ -50,16 +52,36 @@ func NewAPIHandler(store storage.Storage, cfg *config.Config) *APIHandler {
 	}
 }
 
+// uuidToBase32 converts a UUID to a URL-safe Base32 string (without padding)
+// with hyphens every 7 characters for better readability
+func uuidToBase32(id uuid.UUID) string {
+	// Use RFC 4648 Base32 encoding (URL-safe)
+	encoded := base32.StdEncoding.WithPadding(base32.NoPadding).EncodeToString(id[:])
+	// Convert to lowercase for better readability
+	encoded = strings.ToLower(encoded)
+
+	// Insert hyphens every 7 characters
+	var result strings.Builder
+	for i, char := range encoded {
+		if i > 0 && i%7 == 0 {
+			result.WriteRune('-')
+		}
+		result.WriteRune(char)
+	}
+
+	return result.String()
+}
+
 // CreateTest creates a new deliverability test
 // (POST /test)
 func (h *APIHandler) CreateTest(c *gin.Context) {
 	// Generate a unique test ID (no database record created)
 	testID := uuid.New()
 
-	// Generate test email address
+	// Generate test email address using Base32-encoded UUID
 	email := fmt.Sprintf("%s%s@%s",
 		h.config.Email.TestAddressPrefix,
-		testID.String(),
+		uuidToBase32(testID),
 		h.config.Email.Domain,
 	)
 
@@ -94,10 +116,10 @@ func (h *APIHandler) GetTest(c *gin.Context, id openapi_types.UUID) {
 		apiStatus = TestStatusPending
 	}
 
-	// Generate test email address
+	// Generate test email address using Base32-encoded UUID
 	email := fmt.Sprintf("%s%s@%s",
 		h.config.Email.TestAddressPrefix,
-		id.String(),
+		uuidToBase32(id),
 		h.config.Email.Domain,
 	)
 

internal/receiver/receiver.go

@@ -22,6 +22,7 @@
 package receiver
 
 import (
+	"encoding/base32"
 	"encoding/json"
 	"fmt"
 	"io"
@@ -112,8 +113,34 @@ func (r *EmailReceiver) ProcessEmailBytes(rawEmail []byte, recipientEmail string
 	return nil
 }
 
+// base32ToUUID converts a URL-safe Base32 string (without padding) to a UUID
+// Hyphens are ignored during decoding
+func base32ToUUID(encoded string) (uuid.UUID, error) {
+	// Remove hyphens for decoding
+	encoded = strings.ReplaceAll(encoded, "-", "")
+
+	// Convert to uppercase for Base32 decoding
+	encoded = strings.ToUpper(encoded)
+
+	// Decode from Base32
+	decoded, err := base32.StdEncoding.WithPadding(base32.NoPadding).DecodeString(encoded)
+	if err != nil {
+		return uuid.Nil, fmt.Errorf("failed to decode base32: %w", err)
+	}
+
+	// Ensure we have exactly 16 bytes for UUID
+	if len(decoded) != 16 {
+		return uuid.Nil, fmt.Errorf("decoded bytes length is %d, expected 16", len(decoded))
+	}
+
+	// Convert bytes to UUID
+	var id uuid.UUID
+	copy(id[:], decoded)
+	return id, nil
+}
+
 // extractTestID extracts the UUID from the test email address
-// Expected format: test-<uuid>@domain.com
+// Expected format: test-<base32-uuid>@domain.com
 func (r *EmailReceiver) extractTestID(email string) (uuid.UUID, error) {
 	// Remove angle brackets if present (e.g., <test-uuid@domain.com>)
 	email = strings.Trim(email, "<>")
@@ -133,10 +160,10 @@ func (r *EmailReceiver) extractTestID(email string) (uuid.UUID, error) {
 
 	uuidStr := strings.TrimPrefix(localPart, r.config.Email.TestAddressPrefix)
 
-	// Parse UUID
-	testID, err := uuid.Parse(uuidStr)
+	// Decode Base32 to UUID
+	testID, err := base32ToUUID(uuidStr)
 	if err != nil {
-		return uuid.Nil, fmt.Errorf("invalid UUID in email address: %s", uuidStr)
+		return uuid.Nil, fmt.Errorf("invalid Base32 encoding in email address: %s - %w", uuidStr, err)
 	}
 
 	return testID, nil