Say I am in e-mail communication with a British person (in scenario B let is me an American) who is 20 years older than I. I started my first letter with "Dear Sir", but this person replied with "Dear Nyggus" (let's assume Nyggus is my first name). How should I reply? With the first name or the title (in general, Sir, Mrs, Prof, Dr, etc)?
Thanks in advance,
I think it depends on the station of the person to whom you are communicating. If the person is a pier or a subordinate then addressing him or her by first name or "handle" is perfectly acceptable. However if the person is an administrator or superior in business, government or college then i recommend sticking with the more formal address.
I hope this helps,