If i have two sales channel (shop a and shop b) with different domains, and name and mailaddresses, but with the same language, how do i set this up correctly?
right now we have in the checkout header the same mail address because this is given in the snippets. (header.supportInfo)
and even the name in checkout finish in shop b is given from shop a. but in the snippets there it is set as %shop% (checkout.finishHeader) and i would expect, the name then to be taken from the sales channel config
You should duplicate the snippets sets, so you have one snippet set per sales channel. In the administration under Settings -> Snippets you can manage your snippets sets.
You probably want two snippet sets, that use the same (probably the default snippet base file (messages.de-DE) as the starting point. With that setup your are then able to override the snippets for the different sales channels seperately.
In you sales channel settings for you can specify which snippet set should be used for each sales channel.