When you open new messages, some images may not appear immediately. MDOfficeMail disables images to protect you from unknown senders, like spammers, who use images and links to verify that your email address is real.
Here's how to view those images:
Internet Explorer users: Your browser settings may prevent images that are being sent through HTTP from being shown within messages.
You may need to adjust Internet Explorer's mixed content settings to view images sent through HTTP by following the steps below. Please note to be cautious of enabling displays of HTTP content, as some sites may have risky or malicious content that the browser setting is trying to protect you from.
Next time Internet Explorer pops up the warning about mixed content, you can choose whether or not you want the content that wasn't delivered via HTTP to be displayed. Browsers like Mozilla Firefox and Google Chrome may default to not showing you a pop-up in these cases, but will put a warning icon in the browser window as a notification of the non-HTTPS content that the site may contain.