WASHINGTON — Organizing for Action, a group formed to back President Obama’s agenda, has fired one of its fundraisers and acknowledged falling short of its standards as questions were raised Friday about whether the group solicited donations in exchange for access to Obama or White House officials.

Samantha Maltzman, a longtime Democratic fundraiser, has been forced to resign after emails surfaced between her and Dr. Munr Kazmir, a major donor, inviting him to a dinner with Obama and listing prices to attend. The emails conflicted with OFA’s longstanding assertion that its supporters don’t have to pay a set price to attend its summits with the president.