Typically when WP Email Manager is unable to contact the email server, it closes the connection. However, in some hosting environments, WP Email Manager fails to close the connection resulting to a connection request that loops endlessly, resulting to where the website loads really slowly or fails to load completely.
To resolve this, first delete the WP Email Manager constants added to the wp-config.php file, then troubleshoot why the connection fails. If you have configured the Custom Server Configuration Addon, disable it via FTP.
Some of the reasons why the connection fails are:
- Plugin conflicts.
- Firewall conflicts. For a quick test, you can try a different server of the same type i.e. if you are using the cPanel integration, test with a different cPanel server. If this works, then your email server is blocking requests from your WordPress server.
- Usage of the WP_HTTP_BLOCK_EXTERNAL constant in wp-config.php file. You can allow your website to contact the email server by use of the WP_ACCESSIBLE_HOSTS constant. Learn more here.
