@contrex,
@contrex and @everybody else involved in the discussion: What an interesting discussion. I enjoyed reading both sites.
I was born in 1988 but I think that I do understand what contrex is talking about because I am German.
Germans having business ties with the US are sometimes a bit unhappy with the ways the Americans communicate because the perceived lack of respect.
To give an example. Germans typically start a letter or a speech by saying "My much honored ladies and gentlemen." This may sound funny in English but not in our language. There are other greetings if the speaker is talking to gentry, people with an academic degree, soldiers, police officers and so on or if the speaker himself is conservative gentry. In this case the greeting would be more formal and respectful.
So if Germans receive a business related starting with "hey" they sometimes think it is a bit informal. Of course that depends on the individual involved... and of course we do know it is a different culture.
I hope it was a bit helpful.
Until we write again I remain sincerely yours, Sir, with my best wishes and greetings(<--- one of the possibilities to finish a letter in Germany)
LastUnicorn