For years, email marketing has been one of the few permission marketing channels. Of course, there will always be those direct marketers who choose to leverage the email channel without permission. These programs are doomed to suffer everything from disengagement to actual fines and legal persecution.

>Email marketing is constantly evolving, with social media, mobile and ISPs driving most of the change right now. Here are five predictions of how things will change in 2011:

What will the email world look like a year from now? Change used to happen incrementally, but look at the frenetic year that was 2010. Some things only change a little, like deliverability, rendering and spam issues. But the marketing world and email's role in it have begun to shift over the last 12 months, and the repercussions from those changes will be felt as trends for the next 12.

In the past two weeks, our team has received heaps of "apology" emails from various companies, ranging from a consumer packaged goods conglomerate to a travel organization. Either email marketers are making a lot of mistakes -- or they are apology-happy. I think it's the latter.

As I kick off the 2010-2011 conference "tour," I've been preparing a lot of content and talking to a myriad of email marketers across a number of verticals -- all with varying levels of expertise and understanding about the space. One question keeps cropping up: "What's the next new thing for email next year?"

At Thanksgiving time it's traditional to think about what we're thankful for. I've usually limited this practice to my personal life, but I thought this year I'd extend it to the email world. When I put the list together, I was surprised to find that my "thankful list" was probably not the most obvious list of things and focused a lot on the safety and security of email. Why is that?

While cross-channel marketing has become an everyday part of B2C email marketing, some B2B folks express trepidation at the prospect of stepping into the social networking world. There are valid reasons for B2B marketers to wonder whether places like Facebook and Twitter are the right fit for their brand, as well as how cross-channel engagement efforts will come across to their subscriber base. That said, we're firm believers that all brands can pack more punch through cross-channel marketing -- including our B2B friends. It's just a matter of choosing the types of messaging, the channels, and the approaches that will …

I am a huge fan of Groupon*. While not every offer they send me is 100% relevant, I think they get it right more often than not. But this article is not going to focus on the relevance of their daily offer emails. Instead, I'd like to discuss a recent reminder email they sent me. I'm constantly preaching the importance of sending targeted, timely, valuable emails to people who have subscribed. This reminder email from Groupon hits on all four points.

Years of participating in dozens of debates and arguments in the email-marketing industry make me wonder one thing: Can't we agree on anything? Today, email is under attack, from within our own companies, outside perceptions and, sad to say, even other email marketers. We will be in a stronger position to champion email as an invaluable communication and marketing channel if we can agree on some of the most fundamental issues in our industry.

The challenge for every forward-looking business is to always keep an eye out for what circumstances or threats may prove disruptive. The most successful businesses do not merely aim to delay the arrival of a harsher climate or more competitive environment, but seek ways to outpace the passage of time by staying in front of threats. So what are the biggest threats to your email business, and how can you ward them off or dodge them entirely?