This reasonably innocuous email promotion from a travel company is tailored for the Northern Hemisphere but sent to prospects in the Southern Hemisphere. If they'd tailored their message I could have received an email saying "Make Summer last longer..." The only email newsletters I'm involved with are tailored to recipients in a single country and a single timezone so we don't have some of the issues that internationally focussed companies have. So, what allowances for season, timezone, etc do you make?