PHP error messages undefined index

I have recently started to receive the following error messages at the top of my wordpress site:

Notice: Undefined index: bdea_filter_options in /var/www/vhosts/cappellaniauniroma3.org/httpdocs/wp-content/plugins/block-disposable-email-addresses/bdea.php on line 140

Notice: Undefined index: bdea_filter_options in /var/www/vhosts/cappellaniauniroma3.org/httpdocs/wp-content/plugins/block-disposable-email-addresses/bdea.php on line 144

Notice: Undefined index: bdea_filter_options in /var/www/vhosts/cappellaniauniroma3.org/httpdocs/wp-content/plugins/block-disposable-email-addresses/bdea.php on line 149

Until this is fixed I’m afraid I must disable this plugin…