World Postcard Day (1 October)

"The day was launched in 2020 by Postcrossing, the website platform for physical postcard exchange, and the print production company Finepaper, following the 150th anniversary of the postcard in 2019." (Crystal)
https://www.postcrossing.com/
On 1 October 1869, the Austrian Post Office "put into practice" the suggestion by "an Austro-Hungarian professor from Vienna" for a practical and cheap method of sending short messages.
More early history here:
https://en.wikipedia.org/wiki/Postcard
Reached England in the 1890s, when _The Standard_ described it as a "craze".
I take this a bit more personally than other Days.
I have a box of (unwritten) postcards -- new, old, beautiful, ugly, interesting and...strange.
I would like to send them all (one by one, in the mail) before I become unable.
Maybe I'll try Postcrossing, though I'm not sure it's what I'm looking for. I will also send them to people I know. I hope.