This is quite often, and quite incorrectly, called Stop The Pigeon, and I'm pleased that a site other than mine has got it's facts spot on again.
This featured Dick Dastardly, Zilly and Klunk as 3 people whose sole job it was to stop a carrier pigeon getting it's message across to wherever it was going.
Mutley also helped DD quite often, and during an episode it wasn't unheard of that he would gain a medal for bravery. Within minutes however, he'd have it stripped from his fur after a plan were disasterously wrong. Snagga Fragga Ragga.
Do You Remember Dastardly and Muttley in their Flying Machines?
Do You Remember Dastardly and Muttley in their Flying Machines?