How HTML Email Works
Before you can start designing, coding, and sending HTML emails, you should know how it works and what tools you’ll need. Here’s some background information every email designer and marketer should know…
The Multipart/Alternative MIME Format
The most important thing you need to know about HTML email is that you can’t just attach an HTML file and a bunch of images to a message and hit “send.” Most of the time, your recipients’ email applications will break all the paths to your image files (because they’ll move your images into temporary folders on your hard drive). And you can’t just paste all your code into your email application, either. Most email apps send messages in “plain-text” format by default, so the HTML won’t render. Your recipients would just see all that raw source code, instead of the pretty email it’s supposed to render.
You need to send HTML email from your server in “Multipart-Alternative MIME format.”Basically, that means your mail transfer agent bundles your HTML code, PLUS a plain-text version of the message, together into one email. That way, if a recipient can’t view
your beautiful HTML email, the good-old-fashioned plain-text version of your message is auto-magically displayed. It’s kind of a nerdy gobbledy-geek thing, which is why a lot of people mess things up when they try to send HTML email themselves. You either need to program a script to send email in multipart/alternative MIME format.
Image Files in HTML Email
Embedding images and photos into messages is the number one reason people want to send HTML email. The proper way to handle images in HTML email is to host them on a web server, then “pull them in” to your HTML email, using “absolute paths” in your code. Basically, you can’t send the graphics along with your message. You host the graphics on a web server, and then the code in your HTML email downloads them whenever the message is opened.
Incidentally, this is how “open tracking” works. You place a tiny, invisible graphic into the email, and then track when it’s downloaded. HTML email, not plain-text, and why the new email applications that block images by default (to protect your privacy) can screw up your open rate stats.
HTML Email Hosting Services
When it comes to hosting the images for your HTML email, you really need your own server to do it. Don’t try hosting images on a free “image hosting service,” because those websites often put scripts in place to prevent you from linking to them in emails (they can’t handle all the traffic). And since you really do get what you pay for, free image hosting services tend to be pretty unreliable under heavy traffic conditions. Also, spammers use free image hosting services all the time, to “cover their tracks.” If you don’t want to look like a spammer, use your own web server. If you use an email marketing service they usually come with a newsletter builder tool with image hosting capabilities built-in.
Delivering HTML Email
Many newbies make the mistake of setting up forwarding lists, or “CC’ing” copies of a message to all their customers. This causes all sorts of problems, like when a customer hits, “reply to all.” Plus, there’s no way to do any kind of individual tracking or personalization when they CC: a big group like that. Finally, it just looks so unprofessional and impersonal when recipients can see your entire list of other recipients like that.
That’s why when a direct email marketing system sends your campaign, we take your message and send it one at a time to each recipient on your list (really, really fast). Unlike your or computer linked to your local ISP (which probably has a standard monthly bandwidth limit), email marketing vendors like us use dedicated mail servers that are capable of sending hundreds of thousands of emails (even millions, for larger vendors) per hour.