Peskov was responding to a question from CNN on a conference call with reporters.
Cohen -- who was executive vice president of the Trump Organization at the time he sent the email -- said Monday that he had contacted the Kremlin for assistance in mid-January 2016 about building a Trump Tower in Moscow when the mogul was running for president, but denied that the project was related to Trump's campaign. But the revelation appears to contradict Trump's vehement denials of any such business connections to Russia in the past.
Cohen told CNN on Monday his message to Peskov was "an email that went unanswered that was solely regarding a real estate deal and nothing more."
Peskov confirmed that his office had located a copy of the email, which said the development deal wasn't moving forward and requested support.
He said the email was sent to the public "Press Office of the Kremlin" address -- which receives thousands of queries, relevant or otherwise -- and denied knowing Cohen personally.
While the Kremlin seeks to quickly answer queries related to the activities of the Russian president, Peskov said, those related to business are not normally responded to or passed up to Putin.
"This email said that a certain Russian company together with certain individuals is pursuing the goal of building a skyscraper in the 'Moscow City' district, but things aren't going well and they asked for help with some advice on moving this project forward," Peskov said. "But, since, I repeat again, we do not react to such business topics -- this is not our work -- we left it unanswered."
He added: "We cannot discuss with President Putin hundreds and thousands of different requests, which, by the way, come from a variety of countries."
Cohen revealed Monday that he had made the overture to Moscow at a point well into Trump's presidential campaign.
"The Trump Moscow proposal was simply one of many development opportunities that the Trump Organization considered and ultimately rejected," Cohen said in a written statement.
"In late January 2016, I abandoned the Moscow proposal because I lost confidence that the prospective licensee would be able to obtain the real estate, financing and government approvals necessary to bring the proposal to fruition," he added. "It was a building proposal that did not succeed and nothing more."
Cohen's own attorney provided documents to the House intelligence committee that included a reference to the Moscow project.
Cohen has been a central focus for investigators on the House intelligence committee who are digging into the Trump campaign's ties to Russia. He is one of only two people to have been subpoenaed by the committee so far; the other is former Trump national security adviser Michael Flynn.
Trump's involvement and awareness of the negotiations remains unclear and there is no public record that Trump has ever spoken about the effort to build a Trump Tower in Moscow in 2015 and 2016. Trump denied having any business interests in Russia in July 2016, tweeting, "for the record, I have ZERO investments in Russia."