What is the proper etiquette to reply to someone who uses their full name in their first email, then a shortened version in subsequent emails? (In a business situation, for people I haven't met)
E.g. if their first contact with me is;
I will respond to their question, and they might reply;
"Thank you, is 9am Friday ok?
When I reply to say that time is fine, should I take the shortened name as if it were someone saying "Please, call me Barb", or stick to the more formal "Barbara"?