Outlook signature images not displaying: blocked, blank and broken logos explained

Outlook signature images not displaying is one problem with two sides: what you did when you built the signature, and what the reader’s Outlook does when your message arrives. Microsoft’s pages show that Outlook is set by default to block automatic picture downloads from the internet, that plain text email cannot show pictures inside the message, and that one way of building a signature can turn pictures into attachments. This article uses Microsoft’s signature page, its message format page and its page on blocked automatic picture downloads, all read in October 2026.

Outlook signature images not displaying: start with what the reader sees

Microsoft’s pages never use the phrase “red X”, so we cannot quote it on that symptom. What the pages do describe is a short list of causes, and the table below ties each likely sight to one of them. Treat the third column as the place to begin, not as a diagnosis you can skip testing.

What the reader sees	Likely cause	Where Microsoft describes it
An empty box or broken-picture icon, plus a bar at the top of the message	Pictures blocked by default	Block or unblock automatic picture downloads
Text signature, no logo, no box at all	Message in plain text	Message format page
Logo as a separate attachment	Signature built with VML tags	Signature page, classic Outlook notes
Logo on your screen, missing on the phone	A mobile setting hides linked pictures	Outlook for Android and iOS pages
Signature missing on one Outlook but not another	Signatures are made in each Outlook separately	Signature page, notes

The first row is by far the one that causes the most support emails, so it comes first below.

Outlook signature images not displaying because pictures are blocked

Microsoft’s page says Outlook is configured by default to block automatic picture downloads from the internet. Its listed reasons include protecting the computer, avoiding offensive material when external content is linked to the message, saving bandwidth, and avoiding tracking pixels. None of that is about your signature specifically. A logo that is loaded from a web address is simply external content like any other.

The reader’s options, as Microsoft lists them:

• One message: choose the bar at the top of the message, then select Download Pictures.
• Every message: on the File tab, choose Options, then Trust Center, then Trust Center Settings, and clear the Don’t download pictures automatically in HTML e-mail messages or RSS items check box.
• One sender or domain: right-click a blocked item and select Add Sender to Safe Senders List or Add the Domain @domain to Safe Senders List.

The first time a customer hears from you, none of those will have happened, so a linked logo may not show, and outlook signature images not displaying becomes your customer’s first impression. You cannot change a stranger’s setting, which is why a signature should not rely on its images alone. More on that further down.

On the phone

Microsoft’s pages for Outlook on Android and iOS describe a Block external images setting. If you or your IT administrator has turned it on, images linked from the internet will not load automatically, and the reader can tap the banner to download them. Ask a colleague who sees no logos on their phone whether that setting is on.

Outlook signature images not displaying in plain text messages

Microsoft’s message format page is plain on this point: the plain text format does not support showing pictures inside the message, though you can include them as attachments. HTML is the default in both classic and new Outlook and is the format that shows pictures inside the message.

There are two ways this bites. You may have switched your own message to plain text. In classic Outlook, select Format Text and choose HTML; in new Outlook, the page describes Options and Switch to plain text to move the other way. Or the reader’s mail program may convert messages. Microsoft says that how a message appears depends on the recipient’s program, and that a message sent as HTML could be converted to plain text if their program is set to convert. That second case is out of your hands. Plain text email signatures shows how to make a signature that still reads well when it happens.

Pictures added the wrong way

For classic Outlook, Microsoft’s steps for adding a logo are these.

1. Open a new message and select Signature, then Signatures.
2. In Select signature to edit, choose the signature that needs the picture.
3. Select the Image button, find the file, and select Insert.
4. To resize, right-click the image and choose Picture, then the Size tab, and keep Lock aspect ratio ticked.
5. Select OK, then OK again.

The same page warns that Vector Markup Language (VML) tags in a signature can make some elements appear as attachments instead of inline images, and recommends the steps above. If your problem is an attachment, not a blank, read signature images showing as attachments, which covers that case on its own.

Five fixes when Outlook signature images are not displaying

1. Reinsert the logo with the Image button instead of pasting it in from Word or a web page.
2. Confirm HTML for the message you are sending.
3. Check the right Outlook. Microsoft says if you have a Microsoft account and use Outlook and Outlook on the web, you create a signature in both, and classic signatures are stored on the device where they were created.
4. Send a test to a second address at a different provider and open it as a stranger would.
5. Look at the picture file itself. If the logo is blurry rather than missing, fixing a blurry signature is the right page.

Where the picture lives

Here Microsoft’s pages leave a gap worth naming. They explain how to insert a picture, but they do not say whether the Image button stores the file inside the message or points to a web address, so we will not guess. What they do say is that blocking applies to linked pictures and other external content. If your signature uses a hosted logo, the web address must open for anyone, without a login, in a private browser window. A logo behind a login page will never load for a customer, however you build the rest.

For choices on size, shape and file type, how to add a logo to an email signature goes through them.

A signature that copes with Outlook signature images not displaying

A reader whose Outlook blocks pictures should still get everything they need. The example below keeps the name, role, email and number in text, with the logo as decoration:

Example only. The company and person are made up. If the logo is blocked, the contact details still read as text.

Where a phone number or link exists only inside a picture, a blocked-image reader cannot use it, and neither can anyone who copies text from the message.

Outlook signature images not displaying across a team

The cause of Outlook signature images not displaying is often not the same on every desk, because each person builds their signature in their own Outlook. A shared design helps only if everyone installs it the same way. emailfooter is a free WordPress plugin that keeps one design and gives each employee numbered steps for their mail app. It does not push signatures into mailboxes, so each person still pastes theirs in, and it is English-only for now.

Frequently asked questions

Why are Outlook signature images not displaying for some people?

Usually their Outlook blocks automatic picture downloads, which Microsoft says is the default setting.

Why are my Outlook signature images not displaying in plain text emails?

Microsoft says plain text does not support showing pictures inside the message. Switch the message to HTML.

How do I get Outlook to show a blocked image?

Select the bar at the top of the message and choose Download Pictures, or add the sender to the Safe Senders List.

Why does my logo show as an attachment?

Microsoft says VML tags in a signature can cause elements to appear as attachments. Reinsert the picture with the Image button.