Not all happenings can or should be interpreted as signs or omens. As this was not a naturally occurring phenomenon, (someone had to place that bird in your mailbox) I would be inclined to see it as a stunt pulled by someone, most likely an unthinking adolescent.
A dead bird is said to be an omen. This is believed by many to be a sign of bad luck.
Nothing. You have a dead bird.
Means nothing but a dead bird. I suggest that something ate the head or it fell off.
that someones fart was really bad and killed alot of birds
It is about a beautiful dead bird and where they pluck its feathers.
When someone puts a dead fish in your mailbox, it means that somebody wants you dead.
It fell after it died.
If a bird breathed when it was dead, then the bird wouldn't be dead. So, no.
There is a product out there called Bird-Deter that is specifically designed for use on a mailbox. It is a very simple design but it keeps birds off of a mailbox with harming them in any way.
Seeing a blackbird could be a good omen. It could also mean heightened awareness spiritually or in your personal life.
it means that the bird is dead nothing can help that