I find it difficult from a professional point of view when people do not indicate their preferred title. We often have approaches from museums, archives and academics regarding loans, potential collaborative projects etc. In the initial response, I always use a formal salutation...when you're dealing with people all over the world from different cultures, I find it is a helpful way to avoid causing offense. Odds are that if the correspondence continues we will wind up on an informal, first name basis, but it's very difficult in the first instance if they don't indicate their preferred title, particularly as many hold PhDs or are senior academics e.g. professors. I've spent many hours googling to find out if the museum director who signed herself 'Jane Doe' is Dr, Ms, Mrs, Miss, Professor, Admiral etc!
There are subtle nuances to modern communication creeping in...for example, when writing a first contact/first response email, I will address the recipient formally (e.g. "Dr Jones"), but will sign off with my forename. The autosignature then puts my full name, position and contact details below my name. It thus gives them all the information they need about me, but at the same time invites them to use my forename if they wish.
There are subtle nuances to modern communication creeping in...for example, when writing a first contact/first response email, I will address the recipient formally (e.g. "Dr Jones"), but will sign off with my forename. The autosignature then puts my full name, position and contact details below my name. It thus gives them all the information they need about me, but at the same time invites them to use my forename if they wish.