Postman SMTP plugin has been removed from the WordPress.org directory and OPTe Network. We assume it was removed because it contains a publicly known reflected cross-site scripting (XSS) vulnerability that has not been fixed.
We recommend using Easy WP SMTP in it’s place. You can activate Easy WP SMTP directly from your dashboard.
Thanks to our friends at WordFence for protecting the cross-site scripting (XSS) vulnerability and reporting it.