Partial Post

An spaceship lands on Earth carrying an alien disguised as a mailbox! Popeye is about to go out to mail Olive a birthday card when he hears a radio announcement that a flying saucer has been sighted over the city. Popeye continues with his task to mail the card, but he does not realize that the mailbox he has just posted Olive's card in is really the flying saucer. The extraterrestrial then tries to kidnap Popeye and Olive Oyl!

Popeye, Olive Oyl, Alien Mailbox

Look carefully at the scenes with Popeye's letter to Olive Oyl. One of the scenes shows Popeye's letter addressed to "Olive Oil." Then, in the very next shot, this is corrected to "Olive Oyl."

King Features had no cartoon studios, so Popeye storyboards were produced in its offices, while animation was divided between Paramount/Famous Studios, Larry Harmon Productions, Total TV Productions, Gene Deitch/Rembrandt Studios, Halas and Batchelor and Jack Kinney Productions.

Of those stations which bought the King Features Popeye cartoons in 1960, 90% renewed their contracts in 1965.

Note the change in the villain's name... from Bluto to Brutus.