I have an e-mail newsletter which I send out once or twice a week. Usually the open rate is between 28% and 36% but my recent newsletter (sent out primo august) only had a open rate around 24%. I'm not sure whether the drop in open rates is caused by people being on vacation, or whether I have a real problem. How are your newsletter open rates affected? Am I the only one with dropping open rates or is it a common problem during these months?