In your iOS devices you have a choice about images that are included in emails. You can have them display or not. This can be an issue depending on the capacity of your device and/or the limits on your data plan.
In my case I prefer to open emails with images on my Mac. I don’t need them to also download on my phone or iPad. Particularly so if they are included in junk mail. Really, I don’t need to get a degree online, buy new windows for my condo, or check out the best prices for hotel rooms in Australia. In addition those embedded images can use a lot of bandwidth.
On the other hand, some folks only have one iOS device and have no Mac. Making sure embedded images in email download properly can be an important issue.
Whatever you choice, you control the downloading of embedded images in the Settings App on your device.
Tap Mail, Contacts, Calendars > Load Remote Images. If the switch is green, the embedded images will open. If the switch is set to white, they will not.
You can turn off Load Remote Images and still manually download email embedded images. Scroll down to the very bottom of the message and click on Load All Images. You don’t have the option of opening individual images. It is all or nothing.
That’s all there is to it.