Over time you've built up a list of contacts, clients and potential customers who are happy to hear from your business over email. That list is both incredibly valuable and not particularly resilient to screw ups. If you start spamming your connections with too many ill-timed or badly written messages, they're likely to unsubscribe. They won't even blink.

To avoid being branded an annoying emailer, it's likely you think long and hard about your email marketing, carefully crafting every word and pondering exactly when to hit send. But you're wasting your time with this last consideration, according to a recent post on top copywriting blog Copyblogger by author Linda Formichelli. She writes:

You've heard it all before:

"Don't send anything on weekdays, on the weekends, or after 5 p.m., because people aren't at their computers."

"Don't email on Mondays because your prospects are too busy, and avoid Fridays because everyone is winding down for the weekend."

"And be sure to stay away from the lunch hour. In fact, the best time to email is on Tuesday at 10:13 a.m."

I call B.S.

What's wrong with all these examples of conventional email marketing wisdom, according to Formichelli? They don't take into account the particularities of your audience, nor the way real world people actually behave when it comes to email.

"Your industry, your business, and your audience have unique demands and desires. You’ve got to test (and test, and test) what works in your world, and then test some more," writes Formichelli, before going on to explain that despite keeping a close on eye on when you get the best results, you'll probably find the timing of your emails really doesn't matter much. In fact, her testing revealed that strangely timed missives were far from ignored:

This past weekend, I did a little experiment. On Sunday at 11:23 a.m.--probably one of the worst times to send a marketing message, according to conventional wisdom--I sent out an email announcing that I was holding a contest to promote my newest e-book.

Within 30 minutes, I had 97 opens, 16 clicks, and 8 sales. Within an hour, the numbers had increased to 212 opens, 39 clicks, and 11 sales. By 3:23, I had 484 opens, 93 clicks, and a total of 27 sales.

By the time I went to bed early that evening, I'd sold 53 e-books.

Following this eye-opening experiment, Formachelli asked around and discovered other email marketers were having similarly good results with emails sent at odd hours.

"You never know when someone is going to be at their computer and ready to buy--so why knock yourself out trying to figure out 'the very best minute' to email? And why apply a hard-and-fast 'waiting' rule, when you’ve got something of value to pass along to your audience?" she concludes, stirring up an active and worthwhile discussion in the post's comments section that's well worth a read.

Do you agree with Formichelli?