Email volume rose 5.4% year-over-year in Q4, according to the Experian CheetahMail 2012 Q4 email benchmark report. The travel industry continued to see above-average growth, of 21.4%, as two-thirds of travel brands increased their volume during the quarter, while media and entertainment brands curtailed mailings by 17%. Each of the 7 verticals tracked increased their email volume quarter-over-quarter, with the overall increase at 26%. On a quarter-over-quarter basis, consumer products and services brands (+36%) and multichannel retailers (+30%) boosted volume the most. Read the rest at MarketingCharts.