This is a guest post from Marianne Cellucci of Net Atlantic.
When designing email newsletters and marketing campaigns, it is important that you consider the limitations presented by email readers. Many users, either by personal preference or email client defaults, are blocking images from being downloaded in the HTML-formatted messages they receive. Thus, it is a good practice for email designers to prepare for both image "off" and "on" scenarios. Here are some of the basics you need to know about using images in email:
Obstacles to Using Image-based Email Campaigns
Blocked or Disabled: It is estimated that approximately 35% of email recipients block all or some of their images; and, by default, several popular webmail services and email clients, such as Google and Outlook, are set to disable images automatically. Many users do not change the default, and therefore never see your images within your email marketing campaigns. Each email client has its own way of rendering blocked images: some display a box with a red "X" placeholder, while others simply gray out the area.
If you neglect to take these default settings into account, you run the risk of recipients reporting your email messages as spam; unsubscribing from your email list because they can’t read your message; and poor email deliverability since fewer messages are actually making it to the inbox.
Spam Filters: Spam filters can’t "read" images, so creating an HTML email that's nothing more than one big image, with little or no text, will trigger spam filters. With a rising surge in image-based spam, your legitimate email marketing campaigns can end up being blocked from delivery, or delivered to the junk folder. We strongly recommend that you avoid using images as your sole content.
Mobile Devices: Most messaging received on mobile devices are text based, so your images are never seen. As more and more portable devices are used for sending and receiving email, you’ll want to ensure that you’re sending both mobile-optimized HTML and text-based versions.