City Hall staffers were reportedly warned by top lawyers for Mayor Adams to be careful about what they put down in writing – since a work email could end up on the cover of The Post.

The advice came during a meeting last month informing staffers about New York’s Freedom of Information Laws – which grants the public the right to seek a wide array of documentation from government agencies – according to a report by Politico.

“Think to yourself as you’re writing the email – is it an email that you would be comfortable having on the front page of the Post?” Deputy Chief Counsel Rahul Agarwal said during the March 1 meeting, according to a recording obtained by the website.

The lawyers advised the workers that what they put in emails, text messages, chats and in calendar entries could later be sought by news outlets or even be used as evidence during investigations, the outlet reported.

Agarwal even cited a 2008 Post story – about how former Mayor Bill de Blasio liked his coffee so sweet that it made a staffer “cringe” – as a cautionary tale of what not to put in an email.

De Blasio aide Elana Leopold asked other staffers to grab the then-mayor a “double espresso w 4 sugars” prompting communications chief Andrew Hagelgans to reply “though I am opposed to 4 sugars.”

“Ya I cringe every time I have to get,” Leopold responded – in the email obtained by The Post after a judge ordered it as part of a Freedom of Information Law civil suit.

Agarwal said during the briefing: “Many of us might agree with that thought –that four sugars in a coffee seems like four too many. But you may not want to put that into an email.”

Adams’ Chief Counsel Brendan McGuire said workers at any level of government can easily get swept up in a scandal because of work communications they “wish they had never sent.” And McGuire said anyone who doesn’t think it can happen to them will be “sorely mistaken because it is a real risk.”

Frequently so many people are required to be on email chains that a third party can accidentally get left on a message they weren’t meant to see.

“You should not expect that there is some semblance of privacy with respect to your official communications,” Agarwal warned.

Agarwal even aptly worried about the presentation from the meeting getting leaked to the press.

“Our instinct is not to circulate the deck to this entire group … given the likelihood that it will get leaked,” Agarwal said.

Special Counsel Bill Heinzen reminded staffers of best practices on work correspondence including not using personal cell phones for work matters, keeping – rather than deleting – work communications, and considering picking up the phone or speaking face-to-face instead of memorializing conversations in writing.

“The best idea is to pick up the phone and call someone or go over and talk to them,” Heinzen said. And if that’s not possible, he advised employees to use an internal chat application, which automatically maintains records of conversations.

City Hall spokesman Fabien Levy told Politico that the point of the meeting wasn’t to instruct people to be less transparent in an attempt to avoid FOIL disclosures. Instead, Levy explained that phone calls are encouraged as a way avoid confusion, that can sometimes occur with written correspondence.

“While we will not go into private conversations, the goal of these refresher courses is to make abundantly clear that all city staffers are expected to understand and comply with laws, rules, and regulations when it comes to retaining documents and other forms of communication,” Levy said.