Fatal error dismissing newsletter opt-in

Firstly, your newsletter opt-in panel really shouldn’t be on every single admin page. That’s just bad form.

Secondly, it doesn’t matter which of the 2 buttons I click, I get a fatal error:

Fatal error: require_once(): Failed opening required '.../public_html/assets/plugins/wp-gmail-smtp/includes/smtp.phpwp-load.php' (include_path='.:/usr/newage/lib/php') in .../public_html/assets/plugins/wp-gmail-smtp/includes/smtp.php on line 4