Sometimes, access to the top starts with something as simple as a stamp. General Motors CEO Mary Barra has noted that she responds to “every single letter” she receives.

Despite leading a nearly $75 billion automaker—and the fact that AI has turned once-tedious tasks such as drafting emails into seconds-long chores—Barra still writes back the old-fashioned way: with pen and paper.

The notes she receives range widely, from loyal Chevrolet drivers sharing their car’s nickname to schoolchildren worried about their family’s future after the closure of a General Motors plant. But positive or negative, the letters still get a response.

“I get [letters] from customers … when their odometer turns over to 200, 300, 400,” Barra said at the New York Times DealBook Summit in December. “I also get letters from consumers who are unhappy about something, and I respond to every single letter I receive. To me, this is such a special business.”

Even as one of the busiest executives in the auto industry—repeatedly topping Fortune’s list of the Most Powerful Women in Business—Barra has consistently treated intentional communication as part of the job. It’s a habit she’s carried throughout her rise at GM, from the assembly line to the C-suite. “You won’t always be right, but no one’s right all the time,” she said in 2023.

And for workers, customers, or even complete strangers, that openness can make the corner office feel more reachable than it seems.

The personalized response can lead to lasting respect and brand loyalty

Carolyn Rodz, founder of a virtual startup accelerator for women, once wrote to Barra as a complete stranger. What she received in return surprised her.

“What really made me respect this woman, who I am a complete stranger to, was the personalization of her response. She not only acknowledged my request and respectfully declined, but she took the time to encourage my pursuit and commended me on my efforts,” Rodz wrote in 2015.

Rodz added that the note did more than close a loop—it built loyalty and lasting respect.

“She validated my vision and affirmed my commitment,” Rodz said. “Truth be told, she built such loyalty in just a couple of paragraphs that I’m considering buying a GM car next time I’m in the market.”

In an era when executives can seem buffered by layers of corporate hierarchy and public relations teams, Barra’s practice stands out. It’s a small gesture with an outsize message: In a business world racing toward automation, the human touch still carries weight.

“It’s people like Mary Barra, however, who remind me that our words have significant value and an opportunity to impact others in ways we may never know,” Rodz said.

Other CEOs are keeping handwritten notes alive, too

Writing letters by hand isn’t just a Barra hallmark. For First Watch CEO Chris Tomasso, old-fashioned notes of appreciation are a leadership ritual.

The head of the $1-billion-a year-in-revenue breakfast and lunch chain sets aside time each month to handwrite congratulatory notes to cooks and dishwashers celebrating major milestones—10, 20, even 30 years with the company. At a business with more than 15,000 employees, Tomasso has penned more than 500 notes and believes the small gesture can have a dramatic impact: acknowledging to workers’ that loyalty isn’t taken for granted.

“Our job is to create an environment where our employees are happy and feel appreciated, and they take care of the rest,” Tomasso said on LinkedIn.

Geoffroy van Raemdonck, now the CEO of Saks, is another executive who leans on personalized outreach. Before the pandemic, he sent three to five handwritten thank-you notes every day. As work shifted to remote and hybrid models, he supplemented them with texts, emails, and quick phone calls—but the intent stayed the same.

“I was taught by great mentors of the power of sending a thank-you note,” van Raemdonck told Fortune in 2023. “It’s really important for me—the moment of ‘thank you’—because I know what it is to receive a thank-you, to be acknowledged.”

Many leaders aren’t just writing handwritten notes, they read them, too—and it could even be the key to a job offer.

For Joey Gonzalez, executive chairman of the upscale boutique fitness brand Barry’s, cold outreach is how he found the person who would one day be his CEO. He previously told Fortune people should be willing to take risks and express their passion; you never know what doors it could open later on.

“If you’re going to cold email someone, and you can’t be passionate about the service or the product or whatever it might be, it’s not going to be a compelling email,” Gonzalez said.

“But if you send someone an email that’s like, ‘Hey, I just want to let you know I’ve been doing Barry’s for a year, and it’s changed my life. This is my résumé, and maybe one day you’ll have something for me’—it just goes a long way.”