Originally Posted by mlseim
You have the right idea though about the image being a remote link.
Not if you want everyone to see them they are not. Linked images are blocked by email programs because they allow the sender to log when people open the email and so if a spam email is accidentally opened not blocking them would tell the spammer that it is worth sending thousands more spam emails to that address.
For images to display without asking the recipient to allow remote access first you need to embed the image into the email itself. You do this by setting up an HTML email with a multipart/related part that contains the base64 encoded copy of the image itself that is then referenced from the img tag in the other section of the email.
For a small image such as a logo you are far better to embed the image in the email rather than link it as it will not make the email all that bigger and will display for everyone instead of just the small percentage you manage to convince to turn off that security feature for your email.