We are a company who used to send out emails to our customers with a static email with the images embedded right in the body of the email.
Now we are using php, Form Processor Pro, so the images are not embedded in the email but they are being stored on the server and are called up from external .txt. file. (I hope this makes sense and is standard protocol).
On a lot of email clients, people are not able to see the images with this new method. (They have to click the "show images' button). I tried to explain to the owner that it has to do with each individual's email settings, but he wants me to ask if there is a way to make it more likely that more people will see it.
Let me know if you need more info.