Auch an Alba

I'm happy to help if I can although we'll probably get told off for speaking English soon.
I think there might be some difference between American and GB/Aus/NZ usage of Dear. It is the more formal form than Hi or Hello and it is pretty common in GB to use to address someone until you feel you are familiar enough to move on to hi or to jump right into a conversation without address. Also how you sign off, the more formal Kind/best regards to cheers or take care depend how well you know the person. What is also very common in GB is a bit of small talk before you get to the point (not only in written communication, also on the phone or in meetings), something about the weather or the weekend or whatever. Americans and most other Nationalities don't usually do that.
I know most Germans think that the lack of a formal address in English makes this all easier but I don't think that is necessarily true, it can be a bit of a minefield.