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_error-handling/test.cerr-05.quota-exceeded.ts

@@ -0,0 +1,273 @@
+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 - start SMTP server for quota tests', async () => {
+  testServer = await startTestServer({
+    port: 2563,
+    tlsEnabled: false,
+    authRequired: false
+  });
+  
+  expect(testServer.port).toEqual(2563);
+});
+
+tap.test('CERR-05: Mailbox quota exceeded - 452 temporary', async () => {
+  // Create server that simulates temporary quota full
+  const quotaServer = net.createServer((socket) => {
+    socket.write('220 Quota Test Server\r\n');
+
+    socket.on('data', (data) => {
+      const command = data.toString().trim();
+      
+      if (command.startsWith('EHLO')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('MAIL FROM')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('RCPT TO')) {
+        socket.write('452 4.2.2 Mailbox full, try again later\r\n');
+      } else if (command === 'QUIT') {
+        socket.write('221 Bye\r\n');
+        socket.end();
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    quotaServer.listen(2564, () => resolve());
+  });
+
+  const smtpClient = createSmtpClient({
+    host: '127.0.0.1',
+    port: 2564,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'user@example.com',
+    subject: 'Quota Test',
+    text: 'Testing quota errors'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/452|mailbox|full|recipient/i);
+  console.log('✅ 452 temporary quota error handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    quotaServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-05: Mailbox quota exceeded - 552 permanent', async () => {
+  // Create server that simulates permanent quota exceeded
+  const quotaServer = net.createServer((socket) => {
+    socket.write('220 Quota Test Server\r\n');
+
+    socket.on('data', (data) => {
+      const command = data.toString().trim();
+      
+      if (command.startsWith('EHLO')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('MAIL FROM')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('RCPT TO')) {
+        socket.write('552 5.2.2 Mailbox quota exceeded\r\n');
+      } else if (command === 'QUIT') {
+        socket.write('221 Bye\r\n');
+        socket.end();
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    quotaServer.listen(2565, () => resolve());
+  });
+
+  const smtpClient = createSmtpClient({
+    host: '127.0.0.1',
+    port: 2565,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'user@example.com',
+    subject: 'Quota Test',
+    text: 'Testing quota errors'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/552|quota|recipient/i);
+  console.log('✅ 552 permanent quota error handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    quotaServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-05: System storage error - 452', async () => {
+  // Create server that simulates system storage issue
+  const storageServer = net.createServer((socket) => {
+    socket.write('220 Storage Test Server\r\n');
+
+    socket.on('data', (data) => {
+      const command = data.toString().trim();
+      
+      if (command.startsWith('EHLO')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('MAIL FROM')) {
+        socket.write('250 OK\r\n');
+      } else if (command.startsWith('RCPT TO')) {
+        socket.write('452 4.3.1 Insufficient system storage\r\n');
+      } else if (command === 'QUIT') {
+        socket.write('221 Bye\r\n');
+        socket.end();
+      }
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    storageServer.listen(2566, () => resolve());
+  });
+
+  const smtpClient = createSmtpClient({
+    host: '127.0.0.1',
+    port: 2566,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'user@example.com',
+    subject: 'Storage Test',
+    text: 'Testing storage errors'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/452|storage|recipient/i);
+  console.log('✅ 452 system storage error handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    storageServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-05: Message too large - 552', async () => {
+  // Create server that simulates message size limit
+  const sizeServer = net.createServer((socket) => {
+    socket.write('220 Size Test Server\r\n');
+    let inData = false;
+
+    socket.on('data', (data) => {
+      const lines = data.toString().split('\r\n');
+      
+      lines.forEach(line => {
+        if (!line && lines[lines.length - 1] === '') return;
+        
+        if (inData) {
+          // We're in DATA mode - look for the terminating dot
+          if (line === '.') {
+            socket.write('552 5.3.4 Message too big for system\r\n');
+            inData = false;
+          }
+          // Otherwise, just consume the data
+        } else {
+          // We're in command mode
+          if (line.startsWith('EHLO')) {
+            socket.write('250-SIZE 1000\r\n250 OK\r\n');
+          } else if (line.startsWith('MAIL FROM')) {
+            socket.write('250 OK\r\n');
+          } else if (line.startsWith('RCPT TO')) {
+            socket.write('250 OK\r\n');
+          } else if (line === 'DATA') {
+            socket.write('354 Send data\r\n');
+            inData = true;
+          } else if (line === 'QUIT') {
+            socket.write('221 Bye\r\n');
+            socket.end();
+          }
+        }
+      });
+    });
+  });
+
+  await new Promise<void>((resolve) => {
+    sizeServer.listen(2567, () => resolve());
+  });
+
+  const smtpClient = createSmtpClient({
+    host: '127.0.0.1',
+    port: 2567,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'user@example.com',
+    subject: 'Large Message Test',
+    text: 'This is supposed to be a large message that exceeds the size limit'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeFalse();
+  console.log('Actual error:', result.error?.message);
+  expect(result.error?.message).toMatch(/552|big|size|data/i);
+  console.log('✅ 552 message size error handled');
+
+  await smtpClient.close();
+  await new Promise<void>((resolve) => {
+    sizeServer.close(() => resolve());
+  });
+});
+
+tap.test('CERR-05: Successful email with normal server', async () => {
+  // Test successful email send with working server
+  const smtpClient = createSmtpClient({
+    host: testServer.hostname,
+    port: testServer.port,
+    secure: false,
+    connectionTimeout: 5000
+  });
+
+  const email = new Email({
+    from: 'sender@example.com',
+    to: 'user@example.com',
+    subject: 'Normal Test',
+    text: 'Testing normal operation'
+  });
+
+  const result = await smtpClient.sendMail(email);
+  
+  expect(result.success).toBeTrue();
+  console.log('✅ Normal email sent successfully');
+
+  await smtpClient.close();
+});
+
+tap.test('cleanup - stop SMTP server', async () => {
+  await stopTestServer(testServer);
+});
+
+export default tap.start();