Mobile marketing has become so pervasive in digital marketing that a huge chunk of digital ad dollars are now being spent on mobile ads. eMarketer predicts that 38% of total digital ad spending will be spent on mobile ads in 2015 and will pass the 50% mark by 2017. Bearing this in mind, it is important that a digital marketer ensures that their emails are mobile-ready and compatible with portable devices with small screens sizes of 7-inches or less.

Designing emails that are compatible with devices with small screens requires a radically different approach from the usual traditional emails. Luckily, the art and science of designing mobile-friendly emails is not as esoteric as it sounds, but is rather a pretty straightforward process that encompasses following a few key tips. This is partly the case because more people around the world own smartphones, with prediction that about 25% of the world population will own smartphones by 2016.

Here are 7 tips to make your email marketing more mobile-friendly:

1. Keep Your Email Width Below 600 Pixels

Even though it’s advisable to keep your desktop or web client emails below 600 pixels, you should take this as an absolute prerequisite when the emails are meant to be viewed on mobile devices. Apart from iOS, almost all other mobile operating systems do not fit emails within the width of the screen. This includes popular OSes such as Android where the user has to manually zoom in/out to catch a full glimpse of the email.

When your email is wider than 300 pixels at the top or near the beginning, it is likely to be displayed on a mobile device as one huge chunk of white space. This is of course the easiest way to make sure the recipient discards the email without reading. Most mobile operating systems with the exception of iOS also turn off images by default so keep this in mind as well.

2. Use Responsive Email Design (RED)

Creating a good user experience is really nothing new on the web. The notion of using responsive email designs, however, is just beginning to pick up steam. Email is one of the most frequently used apps on smartphones. Creating responsive email designs is not something that is technically easy to do. Your email service provider or your market automation vendor, however, should be able to help you accomplish this task.

3. Give Careful Consideration About Image Mapping

Image mapping is generally not recommended for regular desktop emails because of the versatile nature of email clients. For mobile emails, the practice is not recommended either but this time because of image-blocking issues and also because the email’s linkable areas might be at the wrong places that are difficult to click on the screen. Mobile users do not normally expect to see images that have links inside them. Companies that frequently use image mapping when sending emails usually do so with emails that contain one large image in the body with little or no text at all. Such emails, however, tend to have low open rates.

4. Make Sure Your Call To Action Stands Out

Even though ensuring you have a call to action that jumps out at you is important for all types of emails, it is even more critical for mobile emails. Your mobile phone subscribers most likely don’t have the patience to search for your call for action. If there is a link that you would like the recipient to click on, make sure it is strategically placed and the user can easily access it.

5. Earn your Subscribers Trust

When it comes to mobile, the sender of the email is usually a critical consideration for most subscribers. You must have noticed that the first thing that is displayed on emails is the name of the sender. If your name does not ring a bell with your subscribers, your email is likely to either be tossed into the delete bin or simply ignored. If your subscribers fail to open your email, then all your other efforts will have been wasted. Earning trust usually begins way before you even send your first email. You can earn the trust of your subscribers offline using traditional channels or on social networks.

6. Use Short Subject Lines With No More Than 40 Characters

This is really a no-brainer - smaller screens means there is less space to cram your messages. If you need your content to be short and concise, start by trimming your subject line. This applies even to regular desktop emails. A general rule of thumb is to use no more than 40 characters to deliver your message. Try to be creative and interesting. You should also remember that shorter subject lines on emails enjoy the highest open and click rates.

7. Use Prominent Call to Action Buttons

Make sure your call to action buttons as well as your links are given prominence on your emails. You should try and make it easy for users to get to the places you want them with a minimum of hassle. These include places like your signup form, your purchase page, or any other target areas on your emails. If the button to click on is too tiny, you risk frustrating your users who might give up easily. Make sure the clickable buttons are at least 40 x 40 pixels. In the same vein, avoid using menu bars and navigation bars on your mobile emails because it’s usually difficult to size them up adequately. The links that you really need are the call to action, contact email and sharing on social media links.

Another very common mistake that many mobile emails commit is stacking links on top of one another. Usually the space between these links is so tiny that users almost inevitably end up clicking on the wrong links. If you need to stack up links on top of one another, ensure they have ample space between them to allow users to easily navigate to the right links.

The same case applies to using columns. Traditional PC emails often use multi-column layouts. For mobile emails, however, having more than one column means that you compromise on the legibility of your text. A maximum of two columns is recommended since using any more means that your users will require to zoom in or scroll.