Markei SMTP configuration

Markei SMTP configuration for Wordpress Configure WordPress for sending mail via SMTP mail supporting encryption, (basic) auth and xoauth2. Configuration is done via wp-config.php. For SMTP is supports plain connections but also SSL/TLS encryption (SMTPS) and STARTLS encryption. Authentication is possible via normal authentication (basic) and XOAUTH2. For XOAUTH2 authentification as a user (Authorization Code Flow) or service principal (Client Credential Flow) is possible. This makes it possible to mail via Gmail or Microsoft 365. In the WordPress admin interface an e-mail test tool will become available to view the given configuration and let you sent a test mail. This plugin is free, does not add signatures to your mail, no spam and no ad's. How to Activate the plugin in WordPress admin. Add the next line to wordpress/wp-config.php above requireonce(ABSPATH . 'wp-settings.php'); define('SMTP', 'smtp://localhost'); Supported options The configuration supports a URL format. Example: protocol://host:port?optionA=valueA&optionB=valueB. Protocol SMTP Simple configuration, no auth, port 25 define('SMTP', 'smtp://localhost'); Simple con