04 Dec 2006
Spam: The Movie
Every couple of years, someone I know mentions that they’ve been contacted by a firm offering an amazing new way to do video email. “But that doesn’t work, it’ll get blocked by sane email packages!” I’ll say, then they’ll say “No, really, it does work!”, and after a couple of panto-style repetitions I remember how it’s done.
You see, you can’t use Flash in emails (or other plugins), and nowadays even external images aren’t loaded by default (as that can be used to invade privacy), so there isn’t an awful lot to work with. A bulky, silent animated GIF would seem to be the nearest you could get to reliably embedding video in an email.
But Microsoft left a loophole. Years ago, they decided the
img tag wasn’t exciting enough, and so added their own
dynsrc attribute. This lets the page specify a multimedia alternative to the standard
src, meaning in Internet Explorer (and therefore packages such as Outlook that use it to display HTML content) you can display a video using an
img tag, while other browsers show the plain image.
<img src="logo.jpg" dynsrc="spinninglogo.wmv" width="320" height="200" alt="Get your spinny logos here">
By attaching the files to the email (keep the video small and use a widely-compatible codec), you can ensure they’ll appear immediately for most recipients, and linking the image to a web page displaying the video makes it available to those who can’t see it in the email.
<a href="http://rotatinglogos.com/video/"><img src="cid:logofile" dynsrc="cid:spinningfile" width="320" height="200" alt="Get your spinny logos here" border="0"></a>
cid: protocol is used to point to the attachment with the corresponding
Content-Id: header. It’s what your email package does automatically when you send an email that has a local image displayed within the content.)
So if you want to risk annoying people by putting video into emails, that’s all there is to it. Of course, the tricky bit is finding a reliable, reputable and cost-effective way to send out large numbers of emails with fairly big attachments…