By Anne Holland, PresidentIf you want to improve email campaign conversions — at least incrementally — the answer may lie in your customer service department. Here’s why:Every time you send an email broadcast, instead of clicking on hotlinks or order buttons, some percent of recipients will click on “reply to” and send you back a message. What percent? Sherpa Reader Don Hoyt at Deerfield.com (who admittedly is in the business of helping companies handle these replies) says his own house mailings get 20% replies for big offers and 5% for non-offer messages, such as informational newsletters. That sounds a little high to me, but it probably varies a lot based on the quality of your list, your marketplace and your…