When Nancy Tyler emailed the principal of her daughter's charter school with some concerns, including the arrest of a teacher at the school's other campus on sexual assault charges, she was taken aback by the response.

"Oh, you AGAIN," Alfredo de la Rosa, the principal and founder of Miami Arts Charter School, wrote in an email. "I believe you sent me a prior email once before about something you "heard." Of course, just like last time, you are wrong again," he continued. "But that is typical for you."

Tyler had emailed the principal last week because her daughter's English teacher was absent and instead of getting a substitute, the students had been sent to other classrooms. Tyler wanted to know what had happened to the teacher, who she heard had left the school.

"As you can understand, I am very concerned about (my daughter) learning and completing the language arts standards this year," Tyler wrote.

"Actually, I don't understand because you are always complaining about things for little or no reason," de la Rosa said, responding to each line in the email individually.

"How can I get her a more stable learning environment?" Tyler continued in her email.

"You can try another school, maybe?" de la Rosa said, adding that the teacher was out sick for two days but hadn't left the school.

Tyler went on to ask why parents at the charter school's Homestead campus, which her daughter attends, hadn't been notified about the recent arrest of a teacher at the school's Wynwood campus on charges related to a sexual relationship with an underage student.

"Finally, we do watch the news in Homestead," Tyler wrote, "and it's sad our campus did not get an email about the sexual predator at the Wynnewood campus."

"Seriously? How 21st century of you!" he responded to her comment about the news. "Why? What could you have done other than complain and be negative? Where you looking to make a positive contribution? I doubt it."

"The other community is not your community," he continued. "You live many miles away. In fact, I'm sure nobody there even knows who you are. You just like the drama. You will have to satisfy your need for gossip by watching TV. By the why, the proper spelling is W-Y-N-W-O-O-D."

Then, de la Rosa signed his email with a poop emoji.

Tyler acknowledged that this wasn't the first time she had contacted the principal with concerns. Since her daughter enrolled in the publicly funded, privately managed school three years ago, Tyler has emailed the principal numerous times about a variety of issues, including security on campus, teacher turnover, and her desire to start a parent association. She has also met with him in person.

"I'm not his favorite parent," she said.

But despite the previous exchanges, Tyler said she was "upset" by de la Rosa's most recent response.

The principal told the Miami Herald that in retrospect he should have "let cooler heads prevail."

"She got under my skin and I should have known better, but there's a history there," he said. "She has not always been polite on her end toward us."

De la Rosa added that anybody who read Tyler's previous emails would understand his response. Some of Tyler's complaints, like one she posted on social media that the best teachers at the Homestead campus are transferred to Wynwood, simply aren't true, he said.

De la Rosa added that Tyler is always contacting him about something. "The solar eclipse, street lights out in front of the school, staff changes, it's just never-ending," he said. "It's hyperactive concern to the point where it goes beyond reason."

De la Rosa declined to provide previous email exchanges to the Herald, saying he did not want to "delve too much into it publicly" for fear of drawing negative attention to Tyler's daughter.

"In spite of the e-mail exchange that may look bad, I'm really not trying to take on a parent and affect a student," he said.

While de la Rosa said his email exchange with Tyler was "not typical" of his communications with parents, Tyler isn't the first parent to complain about the principal's email etiquette or raise concerns about the school.

The parent of one former student, who asked to remain anonymous to avoid drawing negative attention to her child, emailed de la Rosa at the end of the school year in 2015 to explain why she had decided to move her daughter to another school. She later posted the exchange on Facebook.

"Thank you for that special, albeit unsolicited, evaluation," de la Rosa responded. "I have my own opinion and perspective regarding your message. But I will keep that close to the chest. Sounds like you know a lot about running a school and a business. Who knows? Maybe one day you'll be able to implement all of those great ideas somewhere!"

On a Facebook page called "Unprofessional Leadership at MAC," other parents shared concerns about the school and the principal.

Some parents said de la Rosa's response to complaints points to a lack of accountability at the school. De la Rosa is the principal at both campuses and owns the for-profit charter school management company that helps run the schools. (De la Rosa said the company has waived its fees in recent years and hasn't actually made a profit.) That means parents have little recourse, because the school isn't directly overseen by the Miami-Dade school district.

"For him to be both principal (at the school) and principal in his company and have so little regard for the parents ... I think there should be a little bit more accountability," said the parent whose child left the school in 2015.

In Tyler's case, she did contact the charter school's governing board and it responded by offering to set up a meeting. Tyler rejected the invitation, de la Rosa said. After the Herald contacted de la Rosa, he sent a statement to parents apologizing for the exchange. He did not mention the parent by name but said that she had used "unjustifiably provocative and bad-tempered" language in some of their previous exchanges.

As for the poop emoji, de la Rosa told the Herald that was an accident. "It looks intentional but it wasn't," he said. "I don't even know how that ended up on there."