Don't just take my word for it! I like to check in with other smart folks from time to time and see what they have to say about email deliverability. This time around, I recommend checking out this recent article from iPost's Andrew Kordek, where he shares five solid tips that will allow you to improve your email deliverability. Check it out! It's very good advice.
I first met Andrew back when he worked for daily dealer Groupon, somewhere around a hundred years ago. THAT was a heady time, let me tell you. After a long stint at digital agency Trendline Interactive (which he co-founded), he is now Vice President of Customer Engagement for email service provider iPost, an "Email & Messaging Platform Built for Franchises, Agencies, Associations, Restaurants, Entertainment, Publishing, and Retail."