I still remember how, in an episode of an old "Emergency" or 911- themed TV series (in black and white), the EMT (used to be called the ambulance driver) arrived at the scene and found a young man had his whole arm stuck in a mailbox.

The young man explained that he had regrets right after dropping a letter to his girlfriend in the mailbox.  He wanted the letter back.

It took the EMT (used to be called the ambulance driver) a good hour to get the man  unstuck.  The cop who also responded told the young man, "Once you drop it in the mailbox, you cann't get it back."

The story ended (a lovely melody in the backdrop) when the girlfriend came to the scene and promised the man she would not open the letter. 

It was a wonderful story.

Not as direct at @sjrcpa 's No.  Nonetheless, long story short, the same answer....