In the years before Hillary Clinton announced she would run again for president, her top aides expressed profound concerns in internal emails about how foreign donations to the Clinton Foundation and Bill Clinton’s own moneymaking ventures would affect Mrs. Clinton’s political future.

The emails, obtained by hackers and being gradually released by WikiLeaks this month, also are revealing how efforts to minimize potential conflicts at the foundation led to power struggles and infighting among aides and Mrs. Clinton’s family.

One top aide to Mr. Clinton, Douglas J. Band, noted in an email that the former president had received personal income from some foundation donors and “gets many expensive gifts from them.”

Chelsea Clinton accused her father’s aides of taking “significant sums of money from my parents personally,” of “hustling” during foundation events to win clients for their own business, and of even installing spyware on her chief of staff’s computer.