When to send mail

I had a call with a potential client recently asking me what was the best day to send mail. It’s a question that I did not have a good answer to. Email Insider does have an answer to that question: there is no one day to mail to get the best response.

Even if there were one universal best day to send email, it wouldn’t make sense to send your email the same day as everyone else. In the world of direct mail, a truism was that January was a bad month to mail, being just after the holidays, etc. We had great success with January mailings, precisely because of this thinking. We didn’t have much competition in our customers’ mailboxes.
What you’re trying to find is that magic moment when your customer is online with spare time and mental bandwidth. Think of your own experience. Can you tell me that there is a specific day or time of day when you predictably reach this marketer’s nirvana, week after week? Of course not. You may be bored on the weekend and do work-related browsing, or take a break at work for some well-deserved shopping.

This fits with the data I have seen from clients over the years. And, really, if everyone mailed on the exact same time on the same day, then recipients really would be overwhelmed and not answer any of the mail.