Sending, receiving, and organizing email in Outlook on the web for business
For Outlook on the web, the symptoms described point to an attachment/image handling issue rather than a simple picture-download setting.
Use this troubleshooting path:
- Test in an InPrivate/Incognito browser window.
Open Outlook on the web in a private session and try the same image again. If it works there, clear the browser cache for the normal session. - Test a different browser.
If the issue happens in one browser only, the problem is likely browser-specific. - Test a different network, such as a mobile hotspot.
If images or attachments work on another network, the current firewall, proxy, or network path is likely blocking preview or download. - Check whether the problem affects all attachments or only images.
If PDFs, Word files, and other attachments also fail, this is broader than image rendering. - Check whether the issue affects both received images and images attached to new messages.
Since attached images disappear when moved into the message body, also verify the message format:- In Outlook for Windows, Insert > Pictures can be unavailable or fail in plain text format.
- In new Outlook, check Options > Format and confirm the message is HTML, not Plain Text.
- Ask the sender to resend one test message with the image again.
A corrupted original message or attachment can cause preview and download failures. - If desktop Outlook works but Outlook on the web does not, use desktop Outlook as a temporary workaround for opening or downloading the images.
Relevant product behaviors from the documented issues:
- In Outlook on the web, blocked attachments can appear as a generic placeholder such as “1 Attachment” and may not open.
- In Outlook mobile, externally linked internet images do not load automatically when Block external images is enabled.
- In classic Outlook, a known issue after the May 12, 2026 updates caused some inline images in emails, newsletters, or signatures to show a red X or “The linked image cannot be displayed”; this issue was fixed in later builds.
If the issue occurs in Outlook on the web across browsers, across networks, and for multiple attachment types, that indicates a service-side or mailbox-specific problem rather than a local image setting.
References:
- Can't open or view attachments in Outlook on the web
- Outlook web attachment not open and can't download - Microsoft Q&A
- Troubleshoot attachment problems in Outlook for Windows
- Images are not displayed in emails, newsletters, or signatures in classic Outlook
- Why am I seeing "Some images were blocked" when I open certain emails?
- Why don’t I see images when replying to or forwarding a message?