Orders per email delivered were 0.35 percent in the fourth quarter of 2004, an all-time high and much higher than the previous records - 0.30 percent - achieved during the first and second quarters of 2003, writes Internet Retailer, reporting on DoubleClick figures released yesterday. Click-to-purchase conversions also soared, to 4.8 percent from 4.2 percent in 2003's fourth quarter. That's close to the 4.9 percent record, reached in the fourth quarter of 2002. Despite the rise in orders, revenue per email delivered has remained stable over several years; retail and catalog marketers earned 26 cents per email in the fourth quarter. Email marketing remained stable as bounce-back rates fell to a record low of 9.4 percent in the fourth quarter, according to DoubleClick. Open and click rates declined slightly to 32.6 percent and 8 percent, respectively.