I know this sounds a bit goofy at first, but there really are better times of day and week to send your emails if you want to get them opened. Case in point: I shop at this amazingly inexpensive, all natural/organic grocery store. They send out a newsletter once a month which I love because its chalk full of recipes, information about new products, and at least one coupon. The only problem? They send it out at a really bad time of week for me. Even though I love to read it, it usually takes several days to actually get to it if I don’t forget about it.
Bláithín O’ Reilly Murphy’s article points out that there are two sections of the week that work best, the weekend and the middle of the week. These are the times that people tend to have time to sit down and actually read their emails. Time of day is pretty obvious. Just send it either before they leave for work, or after they will get home. The higher up the list your email is in the inbox the more likely they are to open the email and vice versa.