Here's another great example from Litmus of animation being used to create more interesting email marketing design. Unlike static text, the swipe motion used to provide recipients with a look "under the hood" of their email tool is eye-catching and encourages you to take a deeper dive into the rest of the content. Not to mention the header does an excellent job of explicitly stating what this email is about.
Use your real email signature: Just like using a real reply-to email address, you want to use real contact information within the email and the best way to do that is to include your contact details in the email signature. Giving your readers the opportunity to contact you or connect with you online is a great way to be personal and build a relationship with them.
Will people understand what you’re trying to say? It’s usually better to avoid topics (or opinions) that are complex if many people are extremely passionate about them. For example, sharing almost any opinion about immigration policy is usually a bad move, unless your audience is unusually homogenous. You could agree 99% with someone and still piss them off by using the wrong term just because they have such a strong “either you agree 100% with us, or you’re our enemy” mentality. I once pointed out that I think it’s unacceptable to capture and torture people for years—especially if they aren’t charged with any crime, there’s no evidence they’ve done anything wrong, and they’re children. I got several emails back from people saying, “you have no idea what you’re talking about” or “you should stick to marketing and leave politics to people who understand it.” They took it as commentary on geo-politics. I just said I’m not okay with pointless torture of children. I thought we’d all agree on that.