Republican presidential hopeful Jeb Bush in February proudly published some 300,000 emails from his time as Florida governor in what he called "the spirit of transparency." But during his tenure in Tallahassee, the famous "jeb@jeb.org" was not the only account the chief executive used, the Associated Press reported.

Bush, who liked to style himself as the nation's first "eGovernor," also received messages through another, previously unreported email address: "jeb@gencom.net." People wrote to him there more than 400 times between 1999 and 2004, though a spokesman for the former governor said that Bush was unaware of the account, the AP noted based on official records.

The emails sent to the gencom address, which traces to Tallahassee's ElectroNet Broadband Communications, clearly reached the then-governor, but his replies always came from his well-known account, the news service detailed. In 1999, an message sent to a resident who inquired about appointments to Brevard Community College included a request to "please respond to jeb@jeb.org."

Over time, the second address also seems to have come into disuse: The majority of emails sent to "jeb@gencom.net" were sent in 1999; in 2004, records show only one message reached the account, the AP detailed.

Bush's spokeswoman, Kristy Campbell, said the brother of former President George W. Bush -- who is expected to soon announce his own 2016 White House run -- was unaware of the other email account.

"He doesn't know what that email address is,'' Campbell told the AP on Tuesday.

The scrutiny over Bush's communication habits do not only stem from his massive February release but also from the recent controversy that has engulfed Hillary Clinton. The Democratic presidential frontrunner had been harshly criticized after she admitted earlier this month that she had used her private email account for government business during her four-year tenure as secretary of State.

Jason Baron, an attorney who once served as director of litigation at the National Archives and Records Administration, told the New York Times that Clinton's communication habits were highly unusual.

"It is very difficult to conceive of a scenario -- short of nuclear winter -- where an agency would be justified in allowing its Cabinet-level head officer to solely use a private email communications channel for the conduct of government business," he said.