October 9 is World Post Day, commemorating the date in 1874 that the Universal Postal Union was established. The week surrounding this date is also marked as International Letter Writing Week. My A STAMP A DAY blog has several articles about the Universal Postal Union and the commemorations of it, most extensive are those that appeared on this date in 2016 and one I published yesterday.
I have obtained a number of stamps over the years that specifically celebrate either International Letter Writing Week or World Post Day; many more in my collection mark the Universal Postal Union in some way (I have most of the 1949 omnibus for the UPU’s 75th anniversary, for example). I put together about 90 of my favorites for the slideshow below, titled by catalogue numbers (mostly Scott, but some of the newer stamps bear numbers from Michel, Stanley Gibbons, Thailand Post, and the UPU’s own World Numbering System..
Enjoy the stamps, write some letters (or postcards), and use the posts in your country!