If you include images in your Email Marketing campaigns, users will have to manually confirm that they want to load images within their email client:
This can disrupt your initial email layout and impression, so it’s sometimes useful to embed images when creating a campaign:
This option will display your images even if the user has not allowed images to be displayed:
Embedding images will not automatically load the “tracker” image, which is used for recording “opens” in your campaign reports. Users will still need to confirm they wish to load images (or click a link), in order for it to be recorded as an “open.”
Knowing this, there are certain times when using “embed images” might not produce the best results. If you’re relying on analytics and reporting for your campaigns, it’s best to require users to load all images, because then they are forced to view images if they want to see the complete message (and subsequently load the tracker image at the same time).
Also, embedding images can cause the email file size to be very large, which can slow down campaign sending, and cause inconsistent results in major email clients – so in general it’s not recommended to rely on this feature. Instead, you should craft your email message so as not to depend on image placement, or loading, and have your message still be clear in the case that the subscriber can’t see images.