How can I force email programs to show images send in html email using php?

Question

I am sending an html email with php and it includes an image. Some email programs, such as gMail have a \'display images\' button. The user has to click on that in order for

Answer 1

Doubt it, it would be a security issue if the 'src' of an image opened up a cross site scripting attack.

Cross site request forgery

Customers of a bank in Mexico were attacked in early 2008 with an image tag in email and were sent through their home routers to the wrong website.