It used to be that when you send an email would not have a huge impact on engagement metrics. Because messages linger in the inbox, many messages would continue driving opens and clicks hours and even days after their arrival, once recipients logged in and worked through their new mail. But over the past couple of years, a few developments are promising to have a profound affect on delivery timing:

1. Mobile Audiences: A recent study found that over half of mobile workers check email on their smartphones before they even get dressed in the morning. You can likely assume they checked just before going to bed, while they were out at lunch, and during the commercials while watching the Olympics. Suddenly there is no bad time to send emails, no matter who your audience is.

2. Inbox Clutter: A message lying in wait in an inbox is as likely to be summarily dismissed as it is to be thoroughly triaged. If a subscriber arrives to work on Monday morning to find 8 messages in the inbox, then yes, each one might get the attention it deserves. How many did you have in your inbox this AM? Probably closer to 38. At volume like that, it’s not reasonable to expect our subscribers to give our messages their full attention. If it’s not urgent, personal or in the 90th percentile for relevance, it won’t get a second glance.

3. Social Media: In social media, messages do not linger, but rather appear fleetingly in feeds. This is changing the way our subscribers think about marketing messages. If you miss a tweet or a status update, chances are your company won’t miss its quarterly numbers as a result, nor will your career spin wildly out of control. I expect our audiences will start to think about email in the same way. With priority inboxes and filters and internal triage processes, subscribers are already finding ways of bubbling what is important to the top. The next step is to stop thinking about less important messages as must-read, and view the inbox as a feed of fleeting content as well.

Now is a good time to resume testing of scheduled sends, to see if you have better results first thing in the morning, later in the evening, even on weekends. Email timing is starting to look a lot like social timing, and is increasingly important to results.

Each week on “Emailioration Monday”  we spotlight a single tactic you can implement this week in order to improve your email marketing. Share tips of your own on Twitter at #Emailioration, and see the full collection of Emailioration tips here.