It’s totally up to you. It really is.
Let’s review what happens when you do or do not click on a “show images” option in an email.
When you click on “show images”, or just generally allow images to be shown in an email, that causes remote images to be fetched from the internet. So what are remote images?
There are two ways to put an image or a picture into a rich formatted email message. The first is to include all of the data for the entire image in the email itself. When the email is displayed the image is right there, already on your computer as part of that email.
The other approach is, instead, to include a link to that image in the email, much like a web page might do. When the email is displayed the email program then uses that link to locate and get the image from a server out on the internet, and then displays it exactly like it would display an image on a web page. That’s a remote image. It’s not fetched until it’s displayed.
(Attachments are in a separate category, by the way. They’re with the email but they’re not displayed in the message body. They’re usually displayed at the bottom or as icons.)
Pros and cons of remote images
Remote images allow emails to be much smaller, since the email itself doesn’t need to carry all of the data of the image with it. But there’s another reason senders use them: when your email program fetches an image for an email, that action can be detected. It allows the sender to determine that the email was opened, since the image was fetched in order to be displayed.
Even on large email lists, like mine, image links can be encoded so that I can tell which of the 67,000 subscribers actually bothered to open or view that image.
Now, here’s the problem: senders can be good people, like me, that only use that information for good. Or senders can be spammers.
Now since spammers send to millions of email address, many of which aren’t valid, they can use the information about who opened an email (i.e., viewed an image) to determine which email addresses are real. And once they find that an email address has a real person behind it, they’re going to send it more spam. That’s why most email programs now default to not displaying images unless you want them to be displayed.
Using the information for good
I actually use this information for a couple of different things: one, it tells me which newsletters are actually getting opened and read more than others. It basically tells me what information people are actually interested in. It also tells me who’s stopped opening my newsletter; which subscribers are not looking at what I send at all.
Now, both measurements are inexact – there is no way to tell with 100% accuracy that an email has been opened. Since not everyone views images, the data that I get is thus not 100% accurate; but in a case like mine where I’m sending email to 67,000 people, it’s really helpful for spotting trends over time.
And it’s helpful for my annual mailing list cleanup. The only risk you run by not viewing images on emails you get from me, besides perhaps not seeing a pretty picture, is getting unsubscribed in the spring. If you never enable images from my newsletter and you never click on a link in there, which is another way to infer that you’ve opened the email, then you might get unsubscribed.
Why would I do that? Because, as far as I can tell, since you’re never clicking a link and since you’re never displaying an image, it looks to me like you’re never opening the email and you’re not reading it.
So I assume you’re no longer interested in the newsletter.
All mail services these days, especially the big ones like Google, Outlook.com and Yahoo, actually take that into account when they figure out what is and isn’t spam. If enough people aren’t opening and reading the messages that I send, the messages that I send then have a higher chance of being filtered as spam for everybody. So every spring, I basically unsubscribe everybody that appears to have lost interest, so those that are interested stand a better chance of getting the newsletter.
Other companies do this as well. It’s not a perfect strategy, but it has become important to make sure that everybody that does want the newsletter actually gets it.