Guidelines for Names and Titles: The salutation should typically use the person's last name, along with a "Mr." or "Ms." In general, avoid using "Mrs." or "Miss" unless you are certain of how the woman wants to be addressed. When in doubt, default to using "Ms."
A Note About Email Business Letters. It might be tempting to leave out the closing when you're communicating by email, but don't give in to that temptation. Although no_closing emails are perfectly fine for everyday communication with your friends and teammates, they'll seem brusque – or worse, unprofessional – to people you don't know as well. You should also use a business letter closing when you're corresponding with someone professionally about an important issue, whether it's a new project or a job opportunity.