This plugin sends email through SendGrid using its API. Once you have enabled the plugin then phplist will send all emails, campaigns and system emails, using the plugin.

To revert to using either the php mail() function or an SMTP server, as specified in the config.php file, you should disable the plugin.

See the README file on the GitHub page https://github.com/bramley/phplist-plugin-sendgrid for how to install the plugin.

When you have enabled the plugin there will be a SendGrid group on the Settings page where you can configure the plugin.

• The API key. You must generate an API Key in your SendGrid account and enter the value here.

The plugin does not handle the sending rate, which is done by core phplist as for any other method of sending emails. You should set the throttle, batch size, etc to meet any limit set by SendGrid.

If the call to the SendGrid API fails then an event is added, which you can see on the Event Log page.
As an example, this is the event reported when the API key is invalid

Please raise any questions or problems in the user forum https://discuss.phplist.org/