Today has been one of "those" days. You have them -- you know you do. The day starts with Internet issues, evolves into computer issues, and then, coupled with traffic to the airport and a desperate need to eat, it leaves you a little, well... cranky. But what finally put me over the edge was the barrage of mediocre, "me too," emails in my inbox. For all of you email marketers out there who are doing a good job -- say thanks to this bunch, as they make your good email look great.

If you're in marketing, then you've most likely had at least a few conversations about mobile. The term alone can be confusing; mobile has a lot of meanings and area of concentration (SMS, web-browsing, email viewership, location services, etc.) Because my company is in the email game, we're focused on the impact mobile has on email marketing and deliverability. We released the results of a study we did on mobile email habits ("Email on the Move: The Future of Mobile Messaging") and there were several great takeaways and actionable items for mobile and email marketers. Here are a few things …

For a second there, we thought that the good old text-only version of emails might be headed for extinction -- what with popular smartphones rendering HTML more and more beautifully. But here to rescue the text-only version is the new Facebook email, which displays the text versions of your messages by default. Since they're still going strong, it's important to make sure that text-only versions get your messages across clearly and effectively. Below, find some tips for good-looking text, followed by a glimpse of a few text-only email versions.

Trying to optimize your open rate? Optimize the time of day, or day-of-the week? Increase the reach? Extend the engagement of your email audience? Optimize to the mobile device? What percentage of your database is viewing email on the mobile device today?

Inspiration often comes in strange ways. Mine recently came from my car's GPS navigation, which helped me crystallize my views about what's happening in email marketing and where it has to evolve.

We all know email is hard. Deliverability challenges, narrowing windows of attention, increased clutter, multiple platforms and devices all conspire to drive even the most seasoned email marketers to MediaPost and other trade pubs to read advice on how to make a little bit easier. And all of those challenges are just the external ones - what is going on in and around your subscribers' inboxes that makes it more difficult to connect with them. Email marketers face a litany of internal challenges as well, each of which can create obstacles as aggravating as deliverability hiccups and waning engagement metrics.