Nach langer Recherche fand ich folgende Erklärung unter http://reviews.ebay.com/Beware-of-China-RED-BAND-covers?ugid=10000000009474471

Red Band envelopes were entensively used by Chinese to send letters either locally or abroad in the last century. Mainly written in Chinese and in brush and ink and seldom in English, typed or in fountain pen or biro. Red signifies happiness in eastern culture and a red band envelope shows that the letter contains no bad news. The opposite is the Blue Band envelope which was used by Chinese to break bad news. The Blue Band envelope serves the same purpose as a black bordered mourning cover of the west.

Both Red and Blue Band envelopes are still available in mainland China nowadays thus providing a golden opportunity for forgers to re-create China gems of yesteryears. You can find plenty of fake China classic covers such as Large, Small Dragons, Red Revenues, Dowagers, Local Posts and their combinations on the Internet.

For the trained eye however, no matter how good the fake cancels are and how low the resolutions of the scans, one can still spot the fakes. Reason is the forgers have not perfected the handwriting of yesteryears!!! In fact, for the hundreds of fake Red Band covers in my database, mostly from the Internet, one can easily see that these covers were made by a handful of people and the style of their handwriting, particularly in English is typically modern in style. Therefore, my job as a fake-spotter is made much easier, not by careful study of fake cancels or the fake stamps, just by looking at the handwriting alone.

Also war eine positive, "glückliche" Nachricht im Brief. Die Marken der Deutschen Post wurden vermutlich deswegen verwendet, weil der Brief von einem deutschen Postamt zum anderen dt. Postamt in China geschickt wurde. Ich forsche weiter, wer weiss genaues?

Danke und Gruß
Gerhard