This article is for those using a Code-Your-Own campaign and provides tips for ensuring that your campaign looks great on mobile.

If you're building a CYO campaign, it's important to make sure it's optimized for all email inboxes — and for mobile environments. To aid you in these efforts, we've pulled together a set of mobile-specific tips and a few other important reminders.

Ⓘ	Emma does not offer support for customer-created code, so it's crucial that any person using HTML code is formidably experienced. We do have a talented Design Team that can handle creating the custom HTML coding for you for an additional fee.

Maximum width

Your email should be no wider than 640 pixels. Keeping your mailing 640 pixels wide (or less) ensures that it will display properly on all email clients, including mobile devices. The iPhone has a preview pane of 320px wide and Android's is at 480px. This means that most mobile device users are familiar with scrolling horizontally; however, an email wider than 640 pixels may not fit on one plane and may not display as intended.

Image sizes

Stick to reasonable image sizes - they should be consistent and small. You'll want to make sure that your images fit within the dimensions of your template. We recommend images that are 480 x 480 pixels or smaller.

Check the plaintext version

It's important to pay attention to the plaintext version of your campaign. Although it's becoming less common, some mobile devices will still default to the plaintext version of a campaign.

Don't use Javascript

Not only can Javascript cause browser problems for the recipient, but in the vast majority of cases, it will be stripped out of the email entirely. Additionally, many receiving servers view Javascript as a red flag, which can seriously impact your deliverability.

Don't use Flash

It's just not a good idea to use Flash in your campaigns. This is because using Flash in your email design can affect both delivery and display. Spam filters are particularly hard on Flash and regularly block emails that contain it. If your email does get past the spam filter, you may still run into problems. Most email clients will strip out Flash, leaving your recipient with a blank screen. If animation is important to you, try inserting an animated GIF instead.

Streaming media can't be seen

Streaming media requires an open connection to an external source. As a result, many email clients and associated firewalls will either block the email or disable the streaming media prior to it arriving in an inbox. To communicate this way, we recommend embedding a static image in your design that links to a webpage with the hosted media.

Don't try to embed media files

Some servers will block emails with embedded video and sound files, or they'll strip out the embedded content, leaving your recipient with nothing to view or hear. Rather than embedding the media file, take a screenshot of the video and link that image to the video. You can store the file in your document library or host it directly on your site.