Stamping from afar

People rarely send letters these days.
It’s all electronic now.
The only things that end up in your mailbox are the very important, like official documents, and junk mail.
Tom shuffled through the campaign material, the credit card offers, and local business advertising… tossing it in the trash.
But then there was… the letter.
Plain white envelope, but no return address.
And a Martian stamp, express.
Very rare.
Must be important, because sending anything physical… it must have cost a small fortune.
He opened the envelope, but it was empty.
So, he had it framed to show off the stamp.