We were unable to decode the JSON response from the Mandrill Api mail not send

I am using the standard Code from Source mandrill-api-php/src/Mandrill.php i got error We were unable to decode the JSON response from the Mandrill API and could't send mail . so any suggestion if i got this error to resend mail or queue for failed mail to resend again? Any kind of document by mandrill on this topic please provide.

May be i got this error while their server is down else working fine.

via Chebli Mohamed