update

ts/mail/delivery/classes.smtp.client.ts

@@ -407,8 +407,8 @@ export class SmtpClient {
     // Clear previous extensions
     this.supportedExtensions.clear();
     
-    // Send EHLO
+    // Send EHLO - don't allow pipelining for this command
-    const response = await this.sendCommand(`EHLO ${this.options.domain}`);
+    const response = await this.sendCommand(`EHLO ${this.options.domain}`, false);
     
     // Parse supported extensions
     const lines = response.split('\r\n');
@@ -420,7 +420,13 @@ export class SmtpClient {
       }
     }
     
+    // Check if server supports pipelining
+    this.supportsPipelining = this.supportedExtensions.has('PIPELINING');
+    
     logger.log('debug', `Server supports extensions: ${Array.from(this.supportedExtensions).join(', ')}`);
+    if (this.supportsPipelining) {
+      logger.log('info', 'Server supports PIPELINING - will use for improved performance');
+    }
   }
   
   /**
@@ -661,20 +667,75 @@ export class SmtpClient {
         result.dkimSigned = true;
       }
       
-      // Send MAIL FROM
+      // Get envelope and recipients
       const envelope_from = email.getEnvelopeFrom() || email.from;
-      await this.sendCommand(`MAIL FROM:<${envelope_from}> SIZE=${this.getEmailSize(email)}`);
-      
-      // Send RCPT TO for each recipient
       const recipients = email.getAllRecipients();
       
-      for (const recipient of recipients) {
+      // Check if we can use pipelining for MAIL FROM and RCPT TO commands
+      if (this.supportsPipelining && recipients.length > 0) {
+        logger.log('debug', 'Using SMTP pipelining for sending');
+        
+        // Send MAIL FROM command first (always needed)
+        const mailFromCmd = `MAIL FROM:<${envelope_from}> SIZE=${this.getEmailSize(email)}`;
+        let mailFromResponse: string;
+        
         try {
-          await this.sendCommand(`RCPT TO:<${recipient}>`);
+          mailFromResponse = await this.sendCommand(mailFromCmd);
-          result.acceptedRecipients.push(recipient);
+          
+          if (!mailFromResponse.startsWith('250')) {
+            throw new MtaDeliveryError(
+              `MAIL FROM command failed: ${mailFromResponse}`,
+              {
+                data: {
+                  command: mailFromCmd,
+                  response: mailFromResponse
+                }
+              }
+            );
+          }
         } catch (error) {
-          logger.log('warn', `Recipient ${recipient} rejected: ${error.message}`);
+          logger.log('error', `MAIL FROM failed: ${error.message}`);
-          result.rejectedRecipients.push(recipient);
+          throw error;
+        }
+        
+        // Pipeline all RCPT TO commands
+        const rcptPromises = recipients.map(recipient => {
+          return this.sendCommand(`RCPT TO:<${recipient}>`)
+            .then(response => {
+              if (response.startsWith('250')) {
+                result.acceptedRecipients.push(recipient);
+                return { recipient, accepted: true, response };
+              } else {
+                result.rejectedRecipients.push(recipient);
+                logger.log('warn', `Recipient ${recipient} rejected: ${response}`);
+                return { recipient, accepted: false, response };
+              }
+            })
+            .catch(error => {
+              result.rejectedRecipients.push(recipient);
+              logger.log('warn', `Recipient ${recipient} rejected with error: ${error.message}`);
+              return { recipient, accepted: false, error: error.message };
+            });
+        });
+        
+        // Wait for all RCPT TO commands to complete
+        await Promise.all(rcptPromises);
+      } else {
+        // Fall back to sequential commands if pipelining not supported
+        logger.log('debug', 'Using sequential SMTP commands for sending');
+        
+        // Send MAIL FROM
+        await this.sendCommand(`MAIL FROM:<${envelope_from}> SIZE=${this.getEmailSize(email)}`);
+        
+        // Send RCPT TO for each recipient
+        for (const recipient of recipients) {
+          try {
+            await this.sendCommand(`RCPT TO:<${recipient}>`);
+            result.acceptedRecipients.push(recipient);
+          } catch (error) {
+            logger.log('warn', `Recipient ${recipient} rejected: ${error.message}`);
+            result.rejectedRecipients.push(recipient);
+          }
         }
       }
       
@@ -705,7 +766,7 @@ export class SmtpClient {
         );
       }
       
-      // Format email content (simplified for now)
+      // Format email content efficiently
       const emailContent = await this.getFormattedEmail(email);
       
       // Send email content
@@ -923,7 +984,26 @@ export class SmtpClient {
    * Send SMTP command and wait for response
    * @param command SMTP command to send
    */
-  private async sendCommand(command: string): Promise<string> {
+  // Queue for command pipelining
+  private commandQueue: Array<{
+    command: string;
+    resolve: (response: string) => void;
+    reject: (error: any) => void;
+    timeout: NodeJS.Timeout;
+  }> = [];
+  
+  // Flag to indicate if we're currently processing commands
+  private processingCommands = false;
+  
+  // Flag to indicate if server supports pipelining
+  private supportsPipelining = false;
+  
+  /**
+   * Send an SMTP command and wait for response
+   * @param command SMTP command to send
+   * @param allowPipelining Whether this command can be pipelined
+   */
+  private async sendCommand(command: string, allowPipelining = true): Promise<string> {
     if (!this.socket) {
       throw new MtaConnectionError(
         'Not connected to server',
@@ -946,6 +1026,12 @@ export class SmtpClient {
     return new Promise<string>((resolve, reject) => {
       // Set up timeout for command
       const timeout = setTimeout(() => {
+        // Remove this command from the queue if it times out
+        const index = this.commandQueue.findIndex(item => item.command === command);
+        if (index !== -1) {
+          this.commandQueue.splice(index, 1);
+        }
+        
         reject(MtaTimeoutError.commandTimeout(
           command.split(' ')[0],
           this.options.host,
@@ -953,35 +1039,168 @@ export class SmtpClient {
         ));
       }, this.options.commandTimeout);
       
-      // Send command
+      // Add command to the queue
-      this.socket.write(command + '\r\n', (err) => {
+      this.commandQueue.push({
-        if (err) {
+        command,
-          clearTimeout(timeout);
+        resolve,
-          reject(new MtaConnectionError(
+        reject,
-            `Failed to send command: ${err.message}`,
+        timeout
-            {
-              data: {
-                command: command.split(' ')[0],
-                error: err.message
-              }
-            }
-          ));
-        }
       });
       
+      // Process command queue if we can pipeline or if not currently processing commands
+      if ((this.supportsPipelining && allowPipelining) || !this.processingCommands) {
+        this.processCommandQueue();
+      }
+    });
+  }
+  
+  /**
+   * Process the command queue - either one by one or pipelined if supported
+   */
+  private processCommandQueue(): void {
+    if (this.processingCommands || this.commandQueue.length === 0 || !this.socket) {
+      return;
+    }
+    
+    this.processingCommands = true;
+    
+    try {
+      // If pipelining is supported, send all commands at once
+      if (this.supportsPipelining) {
+        // Send all commands in queue at once
+        const commands = this.commandQueue.map(item => item.command).join('\r\n') + '\r\n';
+        
+        this.socket.write(commands, (err) => {
+          if (err) {
+            // Handle write error for all commands
+            const error = new MtaConnectionError(
+              `Failed to send commands: ${err.message}`,
+              {
+                data: {
+                  error: err.message
+                }
+              }
+            );
+            
+            // Fail all pending commands
+            while (this.commandQueue.length > 0) {
+              const item = this.commandQueue.shift();
+              clearTimeout(item.timeout);
+              item.reject(error);
+            }
+            
+            this.processingCommands = false;
+          }
+        });
+        
+        // Process responses one by one in order
+        this.processResponses();
+      } else {
+        // Process commands one by one if pipelining not supported
+        this.processNextCommand();
+      }
+    } catch (error) {
+      logger.log('error', `Error processing command queue: ${error.message}`);
+      this.processingCommands = false;
+    }
+  }
+  
+  /**
+   * Process the next command in the queue (non-pipelined mode)
+   */
+  private processNextCommand(): void {
+    if (this.commandQueue.length === 0 || !this.socket) {
+      this.processingCommands = false;
+      return;
+    }
+    
+    const currentCommand = this.commandQueue[0];
+    
+    this.socket.write(currentCommand.command + '\r\n', (err) => {
+      if (err) {
+        // Handle write error
+        const error = new MtaConnectionError(
+          `Failed to send command: ${err.message}`,
+          {
+            data: {
+              command: currentCommand.command.split(' ')[0],
+              error: err.message
+            }
+          }
+        );
+        
+        // Remove from queue
+        this.commandQueue.shift();
+        clearTimeout(currentCommand.timeout);
+        currentCommand.reject(error);
+        
+        // Continue with next command
+        this.processNextCommand();
+        return;
+      }
+      
       // Read response
       this.readResponse()
         .then((response) => {
-          clearTimeout(timeout);
+          // Remove from queue and resolve
-          resolve(response);
+          this.commandQueue.shift();
+          clearTimeout(currentCommand.timeout);
+          currentCommand.resolve(response);
+          
+          // Process next command
+          this.processNextCommand();
         })
         .catch((err) => {
-          clearTimeout(timeout);
+          // Remove from queue and reject
-          reject(err);
+          this.commandQueue.shift();
+          clearTimeout(currentCommand.timeout);
+          currentCommand.reject(err);
+          
+          // Process next command
+          this.processNextCommand();
         });
     });
   }
   
+  /**
+   * Process responses for pipelined commands
+   */
+  private async processResponses(): Promise<void> {
+    try {
+      // Process responses for each command in order
+      while (this.commandQueue.length > 0) {
+        const currentCommand = this.commandQueue[0];
+        
+        try {
+          // Wait for response
+          const response = await this.readResponse();
+          
+          // Remove from queue and resolve
+          this.commandQueue.shift();
+          clearTimeout(currentCommand.timeout);
+          currentCommand.resolve(response);
+        } catch (error) {
+          // Remove from queue and reject
+          this.commandQueue.shift();
+          clearTimeout(currentCommand.timeout);
+          currentCommand.reject(error);
+          
+          // Stop processing if this is a critical error
+          if (
+            error instanceof MtaConnectionError &&
+            (error.message.includes('Connection closed') || error.message.includes('Not connected'))
+          ) {
+            break;
+          }
+        }
+      }
+    } catch (error) {
+      logger.log('error', `Error processing responses: ${error.message}`);
+    } finally {
+      this.processingCommands = false;
+    }
+  }
+  
   /**
    * Read response from the server
    */
@@ -999,37 +1218,45 @@ export class SmtpClient {
     }
     
     return new Promise<string>((resolve, reject) => {
-      let responseData = '';
+      // Use an array to collect response chunks instead of string concatenation
+      const responseChunks: Buffer[] = [];
+      
+      // Single function to clean up all listeners
+      const cleanupListeners = () => {
+        if (!this.socket) return;
+        this.socket.removeListener('data', onData);
+        this.socket.removeListener('error', onError);
+        this.socket.removeListener('close', onClose);
+        this.socket.removeListener('end', onEnd);
+      };
       
       const onData = (data: Buffer) => {
-        responseData += data.toString();
+        // Store buffer directly, avoiding unnecessary string conversion
+        responseChunks.push(data);
+        
+        // Convert to string only for response checking
+        const responseData = Buffer.concat(responseChunks).toString();
         
         // Check if this is a complete response
         if (this.isCompleteResponse(responseData)) {
           // Clean up listeners
-          this.socket.removeListener('data', onData);
+          cleanupListeners();
-          this.socket.removeListener('error', onError);
-          this.socket.removeListener('close', onClose);
-          this.socket.removeListener('end', onEnd);
           
-          logger.log('debug', `< ${responseData.trim()}`);
+          const trimmedResponse = responseData.trim();
+          logger.log('debug', `< ${trimmedResponse}`);
           
           // Check if this is an error response
           if (this.isErrorResponse(responseData)) {
             const code = responseData.substring(0, 3);
-            reject(this.createErrorFromResponse(responseData, code));
+            reject(this.createErrorFromResponse(trimmedResponse, code));
           } else {
-            resolve(responseData.trim());
+            resolve(trimmedResponse);
           }
         }
       };
       
       const onError = (err: Error) => {
-        // Clean up listeners
+        cleanupListeners();
-        this.socket.removeListener('data', onData);
-        this.socket.removeListener('error', onError);
-        this.socket.removeListener('close', onClose);
-        this.socket.removeListener('end', onEnd);
         
         reject(new MtaConnectionError(
           `Socket error while waiting for response: ${err.message}`,
@@ -1042,12 +1269,9 @@ export class SmtpClient {
       };
       
       const onClose = () => {
-        // Clean up listeners
+        cleanupListeners();
-        this.socket.removeListener('data', onData);
-        this.socket.removeListener('error', onError);
-        this.socket.removeListener('close', onClose);
-        this.socket.removeListener('end', onEnd);
         
+        const responseData = Buffer.concat(responseChunks).toString();
         reject(new MtaConnectionError(
           'Connection closed while waiting for response',
           {
@@ -1059,12 +1283,9 @@ export class SmtpClient {
       };
       
       const onEnd = () => {
-        // Clean up listeners
+        cleanupListeners();
-        this.socket.removeListener('data', onData);
-        this.socket.removeListener('error', onError);
-        this.socket.removeListener('close', onClose);
-        this.socket.removeListener('end', onEnd);
         
+        const responseData = Buffer.concat(responseChunks).toString();
         reject(new MtaConnectionError(
           'Connection ended while waiting for response',
           {

ts/mail/delivery/classes.smtpserver.ts

@@ -23,7 +23,11 @@ export class SMTPServer {
   private smtpServerOptions: ISmtpServerOptions;
   private server: plugins.net.Server;
   private sessions: Map<plugins.net.Socket | plugins.tls.TLSSocket, ISmtpSession>;
+  private sessionTimeouts: Map<string, NodeJS.Timeout>;
   private hostname: string;
+  private sessionIdCounter: number = 0;
+  private connectionCount: number = 0;
+  private maxConnections: number = 100; // Default max connections
 
   constructor(emailServerRefArg: UnifiedEmailServer, optionsArg: ISmtpServerOptions) {
     console.log('SMTPServer instance is being created...');
@@ -31,21 +35,113 @@ export class SMTPServer {
     this.emailServerRef = emailServerRefArg;
     this.smtpServerOptions = optionsArg;
     this.sessions = new Map();
+    this.sessionTimeouts = new Map();
     this.hostname = optionsArg.hostname || 'mail.lossless.one';
+    this.maxConnections = optionsArg.maxSize || 100;
+
+    // Start session cleanup interval
+    setInterval(() => this.cleanupIdleSessions(), 30000); // Run every 30 seconds
 
     this.server = plugins.net.createServer((socket) => {
+      // Check if we've exceeded maximum connections
+      if (this.connectionCount >= this.maxConnections) {
+        logger.log('warn', `Connection limit reached (${this.maxConnections}), rejecting new connection`);
+        socket.write('421 Too many connections, try again later\r\n');
+        socket.destroy();
+        return;
+      }
+
       this.handleNewConnection(socket);
     });
   }
   
+  /**
+   * Clean up idle sessions
+   * @private
+   */
+  private cleanupIdleSessions(): void {
+    const now = Date.now();
+    const sessionTimeout = this.smtpServerOptions.socketTimeout || 300000; // Default 5 minutes
+    
+    // Check all sessions for timeout
+    for (const [socket, session] of this.sessions.entries()) {
+      if (!session.lastActivity) continue;
+      
+      const idleTime = now - session.lastActivity;
+      if (idleTime > sessionTimeout) {
+        logger.log('info', `Session ${session.id} timed out after ${idleTime}ms of inactivity`);
+        
+        try {
+          // Send timeout message and end connection
+          this.sendResponse(socket, '421 Timeout - closing connection');
+          socket.destroy();
+        } catch (error) {
+          logger.log('error', `Error closing timed out session: ${error.message}`);
+        }
+        
+        // Clean up session
+        this.removeSession(socket);
+      }
+    }
+  }
+  
+  /**
+   * Create a new session ID
+   * @private
+   */
+  private generateSessionId(): string {
+    return `${Date.now()}-${++this.sessionIdCounter}`;
+  }
+  
+  /**
+   * Properly remove a session and clean up resources
+   * @private
+   */
+  private removeSession(socket: plugins.net.Socket | plugins.tls.TLSSocket): void {
+    const session = this.sessions.get(socket);
+    if (!session) return;
+    
+    // Clear session timeout if exists
+    const timeoutId = this.sessionTimeouts.get(session.id);
+    if (timeoutId) {
+      clearTimeout(timeoutId);
+      this.sessionTimeouts.delete(session.id);
+    }
+    
+    // Remove session from map
+    this.sessions.delete(socket);
+    
+    // Decrement connection count
+    this.connectionCount--;
+    
+    logger.log('debug', `Session ${session.id} removed, active connections: ${this.connectionCount}`);
+  }
+  
+  /**
+   * Update last activity timestamp for a session
+   * @private
+   */
+  private updateSessionActivity(socket: plugins.net.Socket | plugins.tls.TLSSocket): void {
+    const session = this.sessions.get(socket);
+    if (!session) return;
+    
+    session.lastActivity = Date.now();
+  }
+
   private async handleNewConnection(socket: plugins.net.Socket): Promise<void> {
     const clientIp = socket.remoteAddress;
     const clientPort = socket.remotePort;
     console.log(`New connection from ${clientIp}:${clientPort}`);
     
+    // Increment connection count
+    this.connectionCount++;
+    
+    // Generate unique session ID
+    const sessionId = this.generateSessionId();
+    
     // Initialize a new session
     this.sessions.set(socket, {
-      id: `${socket.remoteAddress}:${socket.remotePort}`,
+      id: sessionId,
       state: SmtpState.GREETING,
       clientHostname: '',
       mailFrom: '',
@@ -56,6 +152,7 @@ export class SMTPServer {
       remoteAddress: socket.remoteAddress || '',
       secure: false,
       authenticated: false,
+      lastActivity: Date.now(),
       envelope: {
         mailFrom: {
           address: '',
@@ -129,7 +226,29 @@ export class SMTPServer {
     // Send greeting
     this.sendResponse(socket, `220 ${this.hostname} ESMTP Service Ready`);
 
+    // Set session timeout
+    const sessionTimeout = setTimeout(() => {
+      logger.log('info', `Initial connection timeout for session ${sessionId}`);
+      this.sendResponse(socket, '421 Connection timeout');
+      socket.destroy();
+      this.removeSession(socket);
+    }, this.smtpServerOptions.connectionTimeout || 30000);
+    
+    // Store timeout reference
+    this.sessionTimeouts.set(sessionId, sessionTimeout);
+    
     socket.on('data', (data) => {
+      // Clear initial connection timeout on first data
+      const timeoutId = this.sessionTimeouts.get(sessionId);
+      if (timeoutId) {
+        clearTimeout(timeoutId);
+        this.sessionTimeouts.delete(sessionId);
+      }
+      
+      // Update last activity timestamp
+      this.updateSessionActivity(socket);
+      
+      // Process the data
       this.processData(socket, data);
     });
 
@@ -151,16 +270,21 @@ export class SMTPServer {
           details: {
             clientPort,
             state: SmtpState[session.state],
-            from: session.mailFrom || 'not set'
+            from: session.mailFrom || 'not set',
+            sessionId: session.id
           }
         });
       }
+      
+      // Clean up session
+      this.removeSession(socket);
     });
 
     socket.on('error', (err) => {
       const clientIp = socket.remoteAddress;
       const clientPort = socket.remotePort;
-      console.error(`Socket error: ${err.message}`);
+      const session = this.sessions.get(socket);
+      console.error(`Socket error for session ${session?.id}: ${err.message}`);
       
       // Log connection error as security event
       SecurityLogger.getInstance().logEvent({
@@ -172,18 +296,21 @@ export class SMTPServer {
           clientPort,
           error: err.message,
           errorCode: (err as any).code,
-          from: this.sessions.get(socket)?.mailFrom || 'not set'
+          from: session?.mailFrom || 'not set',
+          sessionId: session?.id
         }
       });
       
-      this.sessions.delete(socket);
+      // Clean up session resources
+      this.removeSession(socket);
       socket.destroy();
     });
 
     socket.on('close', () => {
       const clientIp = socket.remoteAddress;
       const clientPort = socket.remotePort;
-      console.log(`Connection closed from ${clientIp}:${clientPort}`);
+      const session = this.sessions.get(socket);
+      console.log(`Connection closed for session ${session?.id} from ${clientIp}:${clientPort}`);
       
       // Log connection closure as security event
       SecurityLogger.getInstance().logEvent({
@@ -193,11 +320,13 @@ export class SMTPServer {
         ipAddress: clientIp,
         details: {
           clientPort,
-          sessionEnded: this.sessions.get(socket)?.connectionEnded || false
+          sessionId: session?.id,
+          sessionEnded: session?.connectionEnded || false
         }
       });
       
-      this.sessions.delete(socket);
+      // Clean up session resources
+      this.removeSession(socket);
     });
   }
 
@@ -240,6 +369,9 @@ export class SMTPServer {
     const session = this.sessions.get(socket);
     if (!session || session.connectionEnded) return;
     
+    // Update session activity timestamp
+    this.updateSessionActivity(socket);
+
     const [command, ...args] = commandLine.split(' ');
     const upperCommand = command.toUpperCase();
 
@@ -431,19 +563,32 @@ export class SMTPServer {
     const session = this.sessions.get(socket);
     if (!session) return;
 
+    // Initialize email data buffer if it doesn't exist
+    if (!session.emailDataChunks) {
+      session.emailDataChunks = [];
+    }
+    
     // Check for end of data marker
     if (data.endsWith('\r\n.\r\n')) {
       // Remove the end of data marker
       const emailData = data.slice(0, -5);
-      session.emailData += emailData;
+      
+      // Add final chunk
+      session.emailDataChunks.push(emailData);
+      
+      // Join chunks efficiently
+      session.emailData = session.emailDataChunks.join('');
+      
+      // Free memory
+      session.emailDataChunks = undefined;
       session.state = SmtpState.FINISHED;
       
       // Save and process the email
       this.saveEmail(socket);
       this.sendResponse(socket, '250 OK: Message accepted for delivery');
     } else {
-      // Accumulate the data
+      // Accumulate the data as chunks
-      session.emailData += data;
+      session.emailDataChunks.push(data);
     }
   }
 
@@ -801,6 +946,4 @@ export class SMTPServer {
     const emailRegex = /^[^\s@]+@[^\s@]+\.[^\s@]+$/;
     return emailRegex.test(email);
   }
-
-  // These methods are defined elsewhere in the class, duplicates removed
 }

ts/mail/delivery/interfaces.ts

@@ -96,6 +96,11 @@ export interface ISmtpSession {
    */
   emailData: string;
   
+  /**
+   * Chunks of email data for more efficient buffer management
+   */
+  emailDataChunks?: string[];
+  
   /**
    * Whether the connection is using TLS
    */
@@ -130,6 +135,11 @@ export interface ISmtpSession {
    * Email processing mode to use for this session
    */
   processingMode?: EmailProcessingMode;
+  
+  /**
+   * Timestamp of last activity for session timeout tracking
+   */
+  lastActivity?: number;
 }
 
 /**