When he discovers that animals from all over the world want to communicate with each other, Dr Dolittle has the wonderful idea of setting up the Swallow Mail, the fastest postal service ever. Doctor Dolittle establishes a swallow mail service for the animals when he discovers that they have their own way of writing. When he discovers that animals from all over the world want to communicate with each other, Dr Dolittle has the wonderful idea of setting up the Swallow Mail, the fastest postal service ever. Doctor Dolittle establishes a swallow mail service for the animals when he discovers that they have their own way of writing.