update

ts/mail/delivery/smtpserver/data-handler.ts

@@ -455,14 +455,103 @@ export class DataHandler implements IDataHandler {
       socket.write(`${response}${SMTP_DEFAULTS.CRLF}`);
       SmtpLogger.logResponse(response, socket);
     } catch (error) {
-      SmtpLogger.error(`Error sending response: ${error instanceof Error ? error.message : String(error)}`, {
-        response,
-        remoteAddress: socket.remoteAddress,
-        remotePort: socket.remotePort,
-        error: error instanceof Error ? error : new Error(String(error))
-      });
-      
-      socket.destroy();
+      // Attempt to recover from specific transient errors
+      if (this.isRecoverableSocketError(error)) {
+        this.handleSocketError(socket, error, response);
+      } else {
+        // Log error for non-recoverable errors
+        SmtpLogger.error(`Error sending response: ${error instanceof Error ? error.message : String(error)}`, {
+          response,
+          remoteAddress: socket.remoteAddress,
+          remotePort: socket.remotePort,
+          error: error instanceof Error ? error : new Error(String(error))
+        });
+      }
+    }
+  }
+  
+  /**
+   * Check if a socket error is potentially recoverable
+   * @param error - The error that occurred
+   * @returns Whether the error is potentially recoverable
+   */
+  private isRecoverableSocketError(error: unknown): boolean {
+    const recoverableErrorCodes = [
+      'EPIPE',       // Broken pipe
+      'ECONNRESET',  // Connection reset by peer
+      'ETIMEDOUT',   // Connection timed out
+      'ECONNABORTED' // Connection aborted
+    ];
+    
+    return (
+      error instanceof Error && 
+      'code' in error && 
+      typeof (error as any).code === 'string' && 
+      recoverableErrorCodes.includes((error as any).code)
+    );
+  }
+  
+  /**
+   * Handle recoverable socket errors with retry logic
+   * @param socket - Client socket
+   * @param error - The error that occurred
+   * @param response - The response that failed to send
+   */
+  private handleSocketError(socket: plugins.net.Socket | plugins.tls.TLSSocket, error: unknown, response: string): void {
+    // Get the session for this socket
+    const session = this.sessionManager.getSession(socket);
+    if (!session) {
+      SmtpLogger.error(`Session not found when handling socket error`);
+      if (!socket.destroyed) {
+        socket.destroy();
+      }
+      return;
+    }
+    
+    // Get error details for logging
+    const errorMessage = error instanceof Error ? error.message : String(error);
+    const errorCode = error instanceof Error && 'code' in error ? (error as any).code : 'UNKNOWN';
+    
+    SmtpLogger.warn(`Recoverable socket error during data handling (${errorCode}): ${errorMessage}`, {
+      sessionId: session.id,
+      remoteAddress: session.remoteAddress,
+      error: error instanceof Error ? error : new Error(String(error))
+    });
+    
+    // Check if socket is already destroyed
+    if (socket.destroyed) {
+      SmtpLogger.info(`Socket already destroyed, cannot retry data operation`);
+      return;
+    }
+    
+    // Check if socket is writeable
+    if (!socket.writable) {
+      SmtpLogger.info(`Socket no longer writable, aborting data recovery attempt`);
+      if (!socket.destroyed) {
+        socket.destroy();
+      }
+      return;
+    }
+    
+    // Attempt to retry the write operation after a short delay
+    setTimeout(() => {
+      try {
+        if (!socket.destroyed && socket.writable) {
+          socket.write(`${response}${SMTP_DEFAULTS.CRLF}`);
+          SmtpLogger.info(`Successfully retried data send operation after error`);
+        } else {
+          SmtpLogger.warn(`Socket no longer available for data retry`);
+          if (!socket.destroyed) {
+            socket.destroy();
+          }
+        }
+      } catch (retryError) {
+        SmtpLogger.error(`Data retry attempt failed: ${retryError instanceof Error ? retryError.message : String(retryError)}`);
+        if (!socket.destroyed) {
+          socket.destroy();
+        }
+      }
+    }, 100); // Short delay before retry
     }
   }
 }