AT&T ( T ) and Telefonica (NYSE: TEF )( OTCPK:TEFOF ) are two investment-grade, high-yielding, and slow-growing telecom stocks that have dominant positions in their home markets. AT&T is primarily a U.S.-based business, whereas Telefonica is primarily European-based, with its home market in Spain, butAs the best-rated high-yield investor community on Seeking Alpha, boasting 1,500+ members and a perfect 5/5 rating from 150+ reviews, we pride ourselves on providing unparalleled value and support.But act fast! ...