As an online retailer, you probably already know that email marketing is one of the most cost-effective forms of digital marketing that you can invest in. You may even diligently compose newsletters to send to your email subscribers every month, encouraging them to shop with you again and keep your brand at the top of their mind. But are you also taking steps to optimize your transactional emails?Transactional emails—which are sent to confirm that a web user has taken a specific action, such as making a purchase or joining a loyalty program—are a great way to interact with customers and increase conversions. These emails often include personalized details, such as items that a shopper has viewed on your site or product recommendations based on previous purchases, and have a significantly higher ROI than bulk emails. In fact, simple 'Welcome to the store' messages generate an average of $5.83 per email, as opposed to just $0.53 on average for bulk emails. If you haven’t optimized your ecommerce store's transactional emails, it's clearly time to start.But what are some of the best ways to make sure your transactional messages have the greatest impact? The transactional email delivery service - Email SMTP has put together a helpful infographic guide to crafting transactional emails. Below are a few of the highlights.Incentivize purchases with special email offers. Studies have shown that including an offer with your transactional emails, such as 10% off a shopper's next purchase, can more than double your revenue per email.Remind shoppers about abandoned shopping cart items. Plenty of online shoppers add items to their virtual shopping cart, but 67.45% of these consumers abandon those carts before they get to the checkout stage. That may sound like a depressing statistic, but fortunately, you can reduce that abandonment rate by up to 40% if you send transactional emails reminding shoppers about the items they left behind. Including the name of the abandoned item in the subject line in your email can increase the open rate by around 10%, and including additional recommended purchases can increase the click-through rate by up to 50%.Good manners pay off. It's always a good idea to send a confirmation email once a shopper makes a purchase off your site, and it's an even better idea to include a phrase like 'Thank you for your purchase' in the subject line. Confirmation emails that don’t include a ‘thank you’ have a 35% lower open rate on average than those that do.Make it as easy as possible for shoppers to connect with you. Want to drastically improve your click-through rate on transactional emails? Just add social media buttons. These links have been shown to increase the click-through rate of an email by 55% on average, and they have the added benefit of allowing you to connect with consumers through multiple online channels.These four tips are certainly not the only strategies you can use to get more out of your transactional emails. Check out the original graphic from Easy SMTP to learn more.