I'm dealing with a German company, hunting for a flat. So far I have filled in a web-form and one of their agents has got back to me. She has addressed me as:
Dear Mr [Lastname]
My understanding of German business customs is that I should remain formal for now.
I believe that if we were corresponding in German, I would simply use:
Sehr geehrte Frau [Lastname]
but we are communicating in English and if there's one thing you can trust the British to do, it's mess around with formality. I've now got the options of
Ms, with no way of knowing the lady's marital status.
Ms acceptable to use to address a lady in Germany?
If answers could also address the German salutation, it might be useful for future visitors to this question.