I have been using Cmandril for sometime untill recently when all mails stopped sending and getting error on frontend "We were unable to decode the JSON response from the Mandrill API" and on accessing the component from administrator side I get this (It seems that the api key you provided is incorrect) error despite having the right key in place.
I've generated new keys severally with no luck. Cmandill was working well for several months but all of a sudden just observed that mails stopped going. I went to the component and found that error! What can be the possible source?