I have a html email which contains a footer image (as an attachment of the html email), which is implemented as follow:
<img width="600" height="151" style="" src="cid:email_footer" alt="My Company">
It works perfectly on Gmail, Apple Mail (ios and mac), and Outlook on my PC. However, the image simply doesn't show in the Outlook app on my iPhone! It only shows the alt-text. How can I resolve this problem?
EDIT: the email displayed fine if it is forwarded from somewhere else.
EDIT-2: looks like it's only a problem with image as attachment. It loads remote images just fine...
EDIT-3: Based on the answer, my investigation leads to the result of adding the following line and it works on all the above email clients/apps now :)