Personally, I don't like it when people refer to me as "Mr". My parents named me Shawn, not "Mr". And because my name is gender-neutral, I often get correspondence addressed to "Ms", which I hate even more. In correspondence, I usually address people by their first names (assuming I know their first names).
I find the use of "Ms" to be hypocritical. Why go from Miss/Mrs to another gender-specific term? In business correspondence, gender shouldn't matter, so a non-gendered salutation (or none) should be used. In personal correspondence, gender and marital status may matter, so anything is fair game.
I'm not expert on etiquette, especially historical etiquette. However, my impression is that it was once appropriate to use separate terminology for both men and women ... Miss for women, and Master for men. But maybe this applied only to young or younger people.
I find the use of "Ms" to be hypocritical. Why go from Miss/Mrs to another gender-specific term? In business correspondence, gender shouldn't matter, so a non-gendered salutation (or none) should be used. In personal correspondence, gender and marital status may matter, so anything is fair game.
I'm not expert on etiquette, especially historical etiquette. However, my impression is that it was once appropriate to use separate terminology for both men and women ... Miss for women, and Master for men. But maybe this applied only to young or younger people.