I have been with a company for six years now. We are very informal with each other and have a fairly laid back culture. The company president is Dave, my boss is Lou, I tell employees who call me Mr. Smith (fake name) that my name is Dennis and that there is no need for formality.
We recently hired a new employee. The fake name I will give her for this post is Ginny Potter. In coming on board with us, Ginny signed all of her e-mails Ms. Potter. When she answers the phone it's, 'Good afternoon, this is Ms. Potter speaking.'
When she calls me, it's, 'Good Morning, Dennis, this is Ms. Potter.' And my response is always, 'Good morning, Ginny, how can I help you?' If I send an e-mail to Ginny, the response is signed by Ms. Potter. Emphasis hers.
She is three levels below me in a different line of report in terms of company hierarchy. So her supervisor's boss reports to someone on the same level as me, if that makes sense.
It got back to me that she thinks I'm disrespectful for not calling her Ms. Potter when I speak to her. When I spoke to others about it, most state that they just ignore it, don't use a name to address her, respond to her queries, and let her call herself what she wants. My boss thinks it's idiotic and that she's not at any level within the company to demand that.
When I told my wife, she replied that it's obviously a button for this woman and I'm being an a**hole by antagonizing her. My counterpoint to this is that nobody in the company gets addressed formally and if I don't call my boss or his boss by anything but their first names, I'm not going to formally address another employee several layers down the hierarchy.
Additional info from OP:
She is older than me by about 20 years. My boss is older than me by 30 years. I agree that hierarchy is irrelevant. The only reason I even mentioned it is because I thought people would ask if I report to her or if she's above me in the corporate hierarchy.
The whole company is informal. A department manager we hired went around and introduced himself as Mr. Green to all the employees.
It was explained to him that we use first names and we don't want employees to feel like there are lines that separate us and we don't like a formal address in the company. He understood and when he next saw the employees he told them to call him Steven.
Another insisted on being Dr. Hart because he had a PhD, even after we advised him of the culture. What happened was that Dr. Hart's direct reports started going to Dr. Hart's supervisor with issues instead of him. Because it felt easier to talk with Paul instead of Dr. Hart. Dr. Hart didn't last long.
I guess I've really taken the culture to heart over the years and it's become important to me.
Here's how people judged OP:
YTA she’s being very polite about how she wants to be addressed and you’re taking a crap all over it. She wants to be Ms. Call her Ms. Your position doesn’t excuse this behavior in fact it makes it worse.
She’s not being “that” polite by demanding she be addressed with an honorific when no one else is. She’s demanding she be addressed with more respect than anyone else at the company.
He gets to decide to be called by his first name, or not. She gets to decide to be called by her first name, or not. Just because he breaks the conventions of basic business etiquette does not mean that she has to, no matter their relative positions. YTA.