The Post Office, located at https://afternoon.dynu.com/ is operated by capey and was established possibly in 2013. The software was originally written by TableCat and has since gone under extensive modifications.
The denizens of the PostOffice are an InternetCult known as the Post Office Butterflies (POBF). Be very warned, they are not as sweet as they may appear.
PostOffice hosts several malicious cloans (^?!*1) that SHOULD BE AVOIDED AT ALL COSTS:
editorial notes:
*1 Cloanz?! Like what? Those are just mirrors. World would be blessed with any good clone of Afternoon/letterbox, because it'll be automatically less mailicious by definition. You can't get more mailicious than current amount of unmoderated shitposts deliberatly allowed by copey