iCloud filters the email I send for spam

Recently I have tried to forward a circulating email about how your mind autocorrects spelling mistakes.

However iCloud's outgoing spam filter did not think this mail was appropriate as it contained

PL3453 F0RW4RD 1F

U CAN R34D 7H15

Telling friends to forward a joke or entertaining content is not that evil.

Is this a new "feature". Is this common?

Do I need to cc myself to check if my mail gets sent?

Normally I don't forward this sort of content, but in this case my dad wanted to send it to me, and he wondered why I never replied. So I had to investigate.

Henrik