If I’m writing a business letter to a female attorney, what is the proper salutation to use?
Dear Sir:
or
Dear Madam:
or
Dear Ms. XXXX:
Or something else. I have no idea what title (Mrs., Ms., Miss) she would prefer professionally.
This is fine.
Could I asked why you thought a woman would be called “Sir”?
Not wanting to flame, just curious.
“Yo, bloodsucking psycho hose beast bitch:”
At least, if you’re writing to my ex.
[SUB]I kid! I kid![/SUB] 
If you have a clue as to her preferred style of address, “Dear Miss X,” “Dear Ms. X,” or “Dear Mrs. X,” as the case may be, is always appropriate.
Ms. as a neutral use is common where one doesn’t know.
But I would use “Dear Attorney X” in preference to all the above. (This is a very technical solecism but a common form of address.)
Blech. All the women attorneys of my acquaintence would rather see “Ms. XXX.” And all the attorneys of my acquaintence will make fun of you behind your back for using “Attorney XXX.” Well, all the attorneys of my acquaintence except Polycarp, I guess. 
It will mark you as a rube.
–Cliffy
Common? With one exception, I’ve never seen or heard this usage. And I’ve been around a female attorney or two.
The exception? I have heard African Americans use this title for lawyers. Otherwise, never.
Not an attorney, just a layman interested in the law. I sit corrected.
(But you do have to admit it’s an improvement over Lightnin’'s suggestion!
Well, I thought about saying something about that, but I think I may know his ex.
You’re not a lawyer? Then for god’s sake, would you please stop giving better answers than me in legal threads? (Other legal threads, obviously.)
I had a case in the U.S. Virgin Islands not long ago and that was the common greeting from lawyers based there as well. Rubes, I tell ya!
–Cliffy
I was thinking “Dear Sir:” might be a generic covering both genders, rather than a gender specific way of address. The way you used to be able to use “he” as a generic reference to either gender.
Thanks for all the answers.
It’s an acceptance letter for a job offer. I don’t think I’ll use this one.
This is brilliant, BTW.
–Cliffy
I live in Northeast PA and I’ve heard people refer to attorneys as Attorney X. I’ve even seen ads using this.
Don’t let Cliffy know!
No one uses the form “Attorney Smith” as a form of address. You don’t say, “Hey, Attorney Smith, that’s a really big brief you have!” To their face, they would be Mr. Smith.
If you don’t know the person to whom you are writing, “Dear Sir or Madam” is appropriate. If you do know the name of the person, and know that the person is female, then the acceptable default is “Ms.”
“YO! Ambulance chaser person!” probably isn’t the most positive choice.
I’ve also seen, in business correspondence:
Atty. Joan Smith
123 Any Street
Anytown AZ 12345
Dear Counsel:
…which I think is acceptable, if a bit impersonal.
Where are you from, Raja? In Australia, we’d never address someone as “Attorney” or “Counsel”, it’d always be “Dear Mr _____,” or “Dear Ms _____,” if you were being extremely formal. If you knew the person, even vaguely, or felt like being casual, it’d be “Dear (first name),”. “Esq” is incredibly wanky, I’ve never seen it used in Australia. In a business context it’s ok to address a letter with the name and address on top, but no actual salutation eg:
Ms Wilhelmina Proudfoot
232 Main St
Pigsville 3480 NSW
Re: Faulty product
I write on behalf of my client, _______, blah blah blah.
I feel odd disagreeing with a lawyer on this, but… I’ve heard “Attorney” used as a form of address plenty of times. I worked for a lawyer, and I would say a majority of the clients who called for him asked for “Attorney X” (most of the rest just asked for him by his first name). Oddly, at another law firm, the attorney there insisted that all his staff refer to him as “Attorney Y”, as opposed to his first name, which was how we addressed our boss. This was in Connecticut, don’t know if it’s a regional thing or not.
RUUUUUUBES!
–Cliffy