Addressing a business letter to a married couple with different last names

[mbogueharpe]

I am not a teacher.

When addressing a business letter to a married couple with different last names, first party a doctor:

Is "Dear Dr. Jones and Ms. Smith"

more correct than "Dear Dr. Jones and Mrs. Smith"?

It seems to me Mrs. Smith would refer to Ms. Smith's mother.

Please advise. - Thanks!

[SoothingDave]

Use "Ms." I don't think "Mrs." is used at all by women who keep their maiden names.