Mark Brownlow (who I don’t think is here in Ams, much to my disappointment) wrote a long assessment of how to determine what is the best time to send email. He walks through the questions and the data that a sender should evaluate when making the decision when to best send email.
I have previously posted about my views on the best time to send email. There is no one best time to send email. In fact, my experience leads me to believe if someone said the best time to send email is at 4pm on Tuesday afternoon then 4pm on Tuesday afternoon would rapidly become the absolute worst time to send email.
It should come as no surprise, then, that I really like Mark’s #4 recommendation.

4. Make the question obsolete
An alternative option to second guessing the best time of day to send out your emails is to do away with the question entirely.
Eh?
Control of timing becomes less critical to success where the recipient either determines the time of send for you (a concept also applied in the one-to-one model described above). Or where the recipient is determined to seek your emails out, irrespective of when you send them.

Send relevant email that recipients want and they will seek you out. They’ll create filters to put your mail in their “must read” mailboxes, they’ll add your sending addresses to their address books, they’ll actively look for your mail and exactly when you send the mail will become less of a variable in response rates.

data • data segmentation • open rate • Relevancy