Answer:

While some married women still prefer to be ad–dressed verbally or in written correspondence as “Mrs. Smith,” in general it is more practical to use “Ms. Smith,” especially in written communication. This avoids the necessity for learning whether a woman is married, currently unmarried, or recently remarried, and is as serviceable as the standard “Mr.” for men. Given that the majority are older women, however, it is safer to use “Mrs.” with widows, since they probably would prefer that to “Ms.”