The email marketing industry has been fascinated with the innovations happening in the inbox over the past couple years, and especially those being led by Gmail. The Promotions Tab, the unsubscribe feature, grid view, image caching, quick actions, the Inbox app and the soon-to-be-launched Google payments functionality called Pony Express are changing the way consumers engage with email.

"Customer journey" is perhaps today's hottest marketing buzz phrase, but it has the potential to revolutionize your email program and deliver better results for your customer as well as your own bottom line.

So you've been "relegated" to the Promotional tabs in Gmail. Accept it and deal with it. Or, embrace it! It is actually good news. Let me explain.

Microsoft may well be the most progressive inbox provider of the moment with its new Outlook app. On the Android, this app ticks all the boxes.