Programming Tutorials

  Few debugging sessions are as frustrating as diagnosing SMTP connection timeouts. You have a functioning Node.js application, valid credentials, and a standard library like Nodemailer, yet the email refuses to send. When integrating IONOS (formerly 1&1) with Node.js, developers frequently encounter generic errors like   ETIMEDOUT ,   ESOCKET , or authentication failures. The issue rarely lies in the credentials themselves. instead, it stems from a mismatch between the  SMTP port  and the  encryption protocol negotiation  (Implicit TLS vs. STARTTLS). This guide dissects the underlying TCP/IP handshake mechanisms causing these failures and provides a copy-paste, production-ready configuration for sending emails securely via IONOS. The Root Cause: Implicit TLS vs. STARTTLS To fix the configuration, you must understand how the connection is established. IONOS supports two primary modes of operation, and Nodemailer requires specific flags for each. Mi...

  There is no frustration quite like a silent failure in software. You test your WooCommerce checkout or Contact Form 7 setup, the UI reports a successful submission, but the email never arrives. On managed hosting platforms like SiteGround, this is rarely a plugin bug. It is a fundamental infrastructure conflict between how WordPress sends mail by default and how modern spam filters trust incoming messages. If you are experiencing undelivered transactional emails or messages landing in spam, increasing the PHP memory limit or reinstalling plugins will not fix it. You must change the transport protocol from  sendmail  to authenticated SMTP. The Root Cause: Why  wp_mail()  Fails on Cloud Hosting To solve the problem, we must understand the execution flow of a standard WordPress email. When a plugin calls  wp_mail() , WordPress invokes the  PHPMailer  class. By default, PHPMailer uses the native PHP function  mail() . On a Linux environment (li...