It's quite common, even the norm these days, to address people by their first names in professional settings, among colleagues.
The thing is that this is also becoming/has become the norm when you get correspondance from strangers when the standard etiquette is to use title + surname, as in all European countries, I suppose.
Now, I think when people address you by your surname only, either orally or in writing, it is irritating.
Well, I personally find title + surname the worst; it's obnoxious and elitist; my (first) name isn't "engineer". I can live with it, though. I just kinda hate people who demand it of others.
Personally I get annoyed only if a sales person addresses me by first name. There is no other setting where I would prefer a stranger to address me using my full name, unless we’re in some context where there are dozens or hundreds of strangers so one can not expect my name is unique.
The thing is that this is also becoming/has become the norm when you get correspondance from strangers when the standard etiquette is to use title + surname, as in all European countries, I suppose.
Now, I think when people address you by your surname only, either orally or in writing, it is irritating.