STS-111 on the way back letter.

The letter was written by cosmonaut Valeriy Korzun (Expedition 5).
Aboard the station the letter was marked with the “ISS” octagonal board souvenir seal and the “Expedition 5” round board souvenir seal.
The text of the letter was marked with the “Russian Segment of International Space Station” board souvenir seal dated June 15, 2002, the day when Endeavour American Space Shuttle (STS-111 flight) undocked from the ISS.
The letter was delivered to Earth by the Endeavour American Space Shuttle. Having been delivered to Earth the letter was sent from Houston to Russia by registered mail.