Ever wondered why you receive all your emails without the images?
If you’re using MS Outlook, Google Mail, Windows Live Hotmail or any of
the quadrillion other email readers that suppress images, chances are
you did.
The reason behind this phenomenon is to protect you against
spammers: By using the images in (HTML) e-mails, spammers can figure
out if your email address is valid!
So how does it work?
When sending out HTML e-mails (ie emails containing layout code,
images etc.), only the text and layout are sent while the images are
kept on a web server. Only when the recipient opens the email and
requests to see the images, the images are loaded from the web server.
This has the advantage that images must only be sent to people
requesting to see them, and the requests are spread over time, thus
optimizing the bandwith usage. But more important: when the images are
requested from the web server, the request can be logged! This way the
sender knows which email addresses have requested the images, and hence
which email addresses are valid!
In a nice picture this is what happens:
This system is used by spammers as well as legitimate email
marketeers: Spammers use it to identify which email addresses are valid
so they know which addresses they can use again (and again and again… 
), while self-respecting email marketeers use it to calculate their open rates.
But in the heat of the spam battle, email marketeers had to give in and
images were suppressed by all major email applications, resulting in
much less trusty open rates (and email marketeer’s headaches)…
There are however a few things email marketeers can do to deal with the issue:
- try to get listed in the address book of the recipient. Senders who
are in the address book are automatically ‘white-listed’ and the images
will always show!
- add a ‘view email online’ link to an online version of the email
- include alt tags for your images describing your images
- use text-based ads
- focus on click-through rates and conversion rates
- …
for more tips: check out the EmailGarage website
