Have something important you want to be read?
Or maybe you want more views on that recent blog post?
Send out your email marketing or 'blog notification' 15 minutes before the top of the hour.
Most people at this time are on their way to a meeting (checking emails as they walk) or waiting for a meeting to start (checking emails or scanning news while waiting).
We find that mid-morning is best but of course test your audience to see what resonates best!