Is the courier services giant still a reliable blue-chip investment?United Parcel Service (UPS -3.38%) was once considered a safe blue chip stock, but it actually declined about 32% over the past three years. The S&P 500 index, which the delivery services company joined in 2002, rallied more than 29% during the same three-year period. Even with reinvested dividends, UPS delivered a negative total return of about 22%.But could it be a good stock to buy and hold again as declining interest rates drive investo ...