Mayor de Blasio claims he barely knew them, but explosive e-mails ­released Friday show that two of his major campaign donors who were later accused of corruption were given the run of City Hall.

Jona Rechnitz, who pleaded guilty in March to making contributions to extract favorable treatment from government officials, had such clout that he wrote the mayor directly on April 28, 2014, asking to serve “on your committe for [sic] ‘combat police corruption.’ ”

Hizzoner forwarded the request to top aide Avi Fink, who sent it on to other officials, including City Hall’s director of appointments at the time.

It’s not clear what the mayor or Fink wrote in their e-mails, because their comments were redacted by City Hall lawyers.

Rechnitz did not get the post.

Meanwhile, Rechnitz’s associate, Jeremy Reichberg, asked City Hall to intervene to lower a $650,000 water bill on a building in Borough Park, Brooklyn, with the matter addressed directly to the first deputy mayor’s chief of staff.

Mayoral spokesman Eric Phillips said Friday that the bill was lowered to $125,304 because of a meter defect, adding that action was normal “in such situations.”

The e-mails, released late Friday in response to a Freedom of Information request, contradict the mayor’s repeated assertions that campaign donors don’t get special access.

They also call into question his claim that he barely knew the two tainted donors.

“It’s not a particularly close relationship,’’ de Blasio told NBC’s “Meet the Press” in April 2016. “I met them first around the time of the general election. I hadn’t known them previously, really haven’t seen them in the last year or more. They supported the effort.”

The e-mails tell a different story.

They show Rechnitz contacted the mayor directly on matters large and small — inviting him to his son’s bris, seeking to exchange thoughts on a controversial production at the Metropolitan Opera, and asking to pop by City Hall to have a Holocaust survivor present Hizzoner with a book.

On April 1, 2014, three months into the administration, Rechnitz forwarded a friend’s application for the job of buildings commissioner.

Hizzoner eagerly accepted.

“I’m all ears, Jona. We’ve actually been looking for additional candidates. I’ve cc’ed my chief of staff laura santucci. Pls send the info to her as well. Thanks,” de Blasio responded little more than hour later.

In November 2014, when Rechnitz asked the Mayor’s Office for help with violations on a building he owned that was accused of being an illegal hotel, a top mayoral aide arranged a meeting at City Hall before she knew the details.

The e-mails show the government doors parted for Rechnitz after he opened his checkbook.

He donated $50,000 to de Blasio’s now-shuttered Campaign for One New York nonprofit, and he and his wife gave de Blasio $9,900 for the 2013 mayoral campaign, the maximum allowed.

Rechnitz then kicked in $102,300 toward a failed effort, spearheaded by the mayor, to help Democrats win control of the state Senate in 2014.

His communications with City Hall suggest he expected that financial support to be rewarded.

When an event manager told Rechnitz he couldn’t bring a guest to an August 2014 barbecue at Gracie Mansion, the donor included Ross Offinger — lead fund-raiser for the mayor’s 2013 campaign and the Campaign for One New York — on his reply.

“Then count me out,” he wrote.

Reichberg donated the maximum $4,950 to de Blasio’s campaign and bundled another $41,650.

In his dealings with City Hall, he also contacted then-mayoral aide Hayley Prim in October 2014 about problems getting city approval for a tax break on one of his buildings, saying he was “directed to” address her. She eventually said the facts in the case were against him.

Responding to Friday’s e-mail revelations, City Hall spokesman Phillips noted that the mayor grants access to many people who have donated nothing to his campaign.

“These two people at times voice the concerns of their community. It’s City Hall’s responsibility to have communication with people like that,” he said. “At the end of the day, they asked for things large and small from city government and didn’t get them.”

The e-mails aren’t the first time evidence has emerged that de Blasio donors have gotten white-glove treatment from the administration.

Last month, a former deputy commissioner alleged that he was fired for refusing to work out a sweetheart deal for restaurant owner and campaign donor Harendra Singh, who owed $1.7 million in rent and penalties on his lease of city-owned land.