(1) Spouse inadvertently opened a piece of junk mail received via USPS and five $1 bills fell out. Careful examination of the other contents of the envelope made no reference to the money.
(2) Yesterday I received an email sent in 2005. Don’t know the sender. The message was “I will see you Monday”.
Most of the header of emails can be forged. This includes the sending date. If you have a good* email program, you can look at the full header and trace the path it took to get to you including the real time stamps of the servers inbetween. It’s possible (but not easy) to tell if the email was just stuck somewhere on a server and finally delivered or if it’s been forged.
Spammers like to change to the date on emails to put them at one end or the other of your email list. It’s possible this is a spammer who put set the message to notify when the email is read (and you’ve foolishly have that setting on!) so they can tell that your email is “live”.
So the space-time continuum is still working fine, then. Except for the money, which I believe is mine.