feat(storage): add comprehensive tests for StorageManager with memory, filesystem, and custom function backends

feat(email): implement EmailSendJob class for robust email delivery with retry logic and MX record resolution

feat(mail): restructure mail module exports for simplified access to core and delivery functionalities

test/suite/smtpclient_edge-cases/test.cedge-05.encoding-issues.ts

@@ -0,0 +1,145 @@
+import { tap, expect } from '@git.zone/tstest/tapbundle';
+import { startTestServer, stopTestServer, type ITestServer } from '../../helpers/server.loader.ts';
+import { createSmtpClient } from '../../../ts/mail/delivery/smtpclient/index.ts';
+import { Email } from '../../../ts/mail/core/classes.email.ts';
+import * as net from 'net';
+
+let testServer: ITestServer;
+
+tap.test('setup test SMTP server', async () => {
+  testServer = await startTestServer({
+    port: 2570,
+    tlsEnabled: false,
+    authRequired: false
+  });
+  expect(testServer).toBeTruthy();
+  expect(testServer.port).toEqual(2570);
+});
+
+tap.test('CEDGE-05: Mixed character encodings in email content', async () => {
+  console.log('Testing mixed character encodings');
+  
+  const smtpClient = createSmtpClient({
+    host: testServer.hostname,
+    port: testServer.port,
+    secure: false,
+    connectionTimeout: 5000,
+    debug: true
+  });
+
+  // Email with mixed encodings
+  const email = new Email({
+    from: 'sender@example.com',
+    to: ['recipient@example.com'],
+    subject: 'Test with émojis 🎉 and spéçiål characters',
+    text: 'Plain text with Unicode: café, naïve, 你好, مرحبا',
+    html: '<p>HTML with entities: caf&eacute;, na&iuml;ve, and emoji 🌟</p>',
+    attachments: [{
+      filename: 'tëst-filé.txt',
+      content: 'Attachment content with special chars: ñ, ü, ß'
+    }]
+  });
+
+  const result = await smtpClient.sendMail(email);
+  console.log(`Result: ${result.messageId ? 'Success' : 'Failed'}`);
+  expect(result).toBeDefined();
+  expect(result.messageId).toBeDefined();
+
+  await smtpClient.close();
+});
+
+tap.test('CEDGE-05: Base64 encoding edge cases', async () => {
+  console.log('Testing Base64 encoding edge cases');
+  
+  const smtpClient = createSmtpClient({
+    host: testServer.hostname,
+    port: testServer.port,
+    secure: false,
+    connectionTimeout: 5000,
+    debug: true
+  });
+
+  // Create various sizes of binary content
+  const sizes = [0, 1, 2, 3, 57, 58, 59, 76, 77];  // Edge cases for base64 line wrapping
+  
+  for (const size of sizes) {
+    const binaryContent = Buffer.alloc(size);
+    for (let i = 0; i < size; i++) {
+      binaryContent[i] = i % 256;
+    }
+    
+    const email = new Email({
+      from: 'sender@example.com',
+      to: ['recipient@example.com'],
+      subject: `Base64 test with ${size} bytes`,
+      text: 'Testing base64 encoding',
+      attachments: [{
+        filename: `test-${size}.bin`,
+        content: binaryContent
+      }]
+    });
+
+    console.log(`  Testing with ${size} byte attachment...`);
+    const result = await smtpClient.sendMail(email);
+    expect(result).toBeDefined();
+    expect(result.messageId).toBeDefined();
+  }
+
+  await smtpClient.close();
+});
+
+tap.test('CEDGE-05: Header encoding (RFC 2047)', async () => {
+  console.log('Testing header encoding (RFC 2047)');
+  
+  const smtpClient = createSmtpClient({
+    host: testServer.hostname,
+    port: testServer.port,
+    secure: false,
+    connectionTimeout: 5000,
+    debug: true
+  });
+
+  // Test various header encodings
+  const testCases = [
+    {
+      subject: 'Simple ASCII subject',
+      from: 'john@example.com'
+    },
+    {
+      subject: 'Subject with émojis 🎉 and spéçiål çhåracters',
+      from: 'john@example.com'
+    },
+    {
+      subject: 'Japanese: こんにちは, Chinese: 你好, Arabic: مرحبا',
+      from: 'yamada@example.com'
+    }
+  ];
+
+  for (const testCase of testCases) {
+    console.log(`  Testing: "${testCase.subject.substring(0, 50)}..."`);
+    
+    const email = new Email({
+      from: testCase.from,
+      to: ['recipient@example.com'],
+      subject: testCase.subject,
+      text: 'Testing header encoding',
+      headers: {
+        'X-Custom': `Custom header with special chars: ${testCase.subject.substring(0, 20)}`
+      }
+    });
+
+    const result = await smtpClient.sendMail(email);
+    expect(result).toBeDefined();
+    expect(result.messageId).toBeDefined();
+  }
+
+  await smtpClient.close();
+});
+
+tap.test('cleanup test SMTP server', async () => {
+  if (testServer) {
+    await stopTestServer(testServer);
+  }
+});
+
+export default tap.start();