问题
My application is sending transactional email through Mandrill. If we include linked images, Gmail doesn't show them by default. That's normal. What's weird is that, in my test email to myself, it doesn't give me an option to "Always display images from" the address that sent the email.
Gmail's help document doesn't even mention this as a possibility.
How can I get Gmail to give my users the option to always display images in my app's emails?
来源：https://stackoverflow.com/questions/19060080/gmail-says-images-are-not-displayed-but-not-always-display-images-from