Fatal error: Uncaught Error: Call to undefined function PostSMTP\Vendor\GuzzleHttp\choose_handler() in /wp-content/plugins/post-smtp/Postman/Postman-Mail/libs/vendor_prefixed/guzzlehttp/guzzle/src/HandlerStack.php on line 39
Sending a test email works. Most emails work. It’s only when I use one plugin that sends a notification that I get the error. The plugin is a custom built plugin and I’m trying to get more info from the author as to how they are sending the notification.