Added plugin link Added invalid From: address detection , correction is to set `admin_email` An automatic Bcc: address can be set by adding path to SMTP URI: `/admin_email` Adding any other path sets automatic Bcc: address, remember to use URL encoding, %40 for `@` SMTP debug to PHP error.log can be turned on by adding query string to SMTP URI: `?debug` Debug level can be set by adding a value: `?debug=4`, possible values: 0,1,2,4