Sources involved with the spread tell us ... The "Real Housewives of D.C." star received an email from Playboy honchos informing her, "There is no opportunity this calendar year to offer you a cover opportunity or place for your pictorial."
Playboy informed Michaele the company would instead feature her on the website -- explaining, "We had hoped an issue would be available to present you in the pages of the magazine first. However, that does not seem likely and we do not want to keep them from our readers any longer."
If it's any consolation -- the Playboy rep told Salahi the pics were, "AMAZING!"