Outlook signature image disappears in plain text replies

An Outlook signature image disappears from a reply, or arrives as an attached file, mostly for one reason: the reply is plain text, and plain text cannot hold pictures. Switch the reply to HTML and insert the signature again. Then fix the setting that made the reply plain, so the next one keeps its image.

Why the image disappears

Microsoft's message format article says plain text "doesn't support showing pictures inside the message, although you can include pictures as attachments." That sentence explains both symptoms. The picture is either dropped or sent as a separate file.

Three things make a reply plain text:

• The reply is composed in plain text. The format is set to plain text for that message, or for all messages.
• You read all mail as plain text. Microsoft says that if you choose to read all email in plain text, "your replies are also sent in plain text format."
• The message you are replying to is plain text. Community threads report that the reply then starts in plain text too, so the image is lost before you type anything.

Switch the reply to HTML in classic Outlook

1. Open the message and select Reply, Reply All, or Forward.
2. If you are working in the Reading Pane, select Pop Out.
3. In the message window, select Format Text > HTML.
4. Select the Message tab, select Signature, and choose your signature from the menu.

Microsoft notes that you can change the format of individual messages, so one reply can be HTML while the rest stay as they are.

Switch the reply to HTML in new Outlook

Microsoft's new Outlook article documents only the switch from HTML to plain text, which is done from Options in the message window. To keep replies in HTML, set the default instead: select Settings, then Mail, then Compose and reply. Under Message format, choose HTML and select Save.

Make HTML the default in classic Outlook

1. Select the File tab, then Options, then Mail.
2. Under Compose messages, in the Compose messages in this format list, select HTML, then select OK.

Turn off the plain text reading setting

If you read all mail as plain text, go to File, then Options, then Trust Center, then Trust Center Settings, then Email Security. Under Read as Plain Text, clear the Read all standard mail in plain text check box.

Microsoft says this setting turns off formatting, pictures and links for the messages you open. To view one plain text message in its original form, open the InfoBar and choose Display as HTML.

When the image arrives as image001.png

If someone else's reply shows up on your side as "image001.png" in place of their picture, the format was set on their end. A 2021 Microsoft Q&A answer explains that the format of a reply is chosen by the person sending it, not by you. Ask them to reply in HTML.

What forum answers get wrong

• "Edit the plain text version of the signature." This swaps the picture for typed text. The logo still cannot come back in a plain text message, because plain text has no way to hold it.

How Sendoff handles this

Sendoff cannot change which format Outlook uses for a reply. It does handle the parts that depend on your signature:

• The signature is built from tables and inline styles, with no VML tags. Microsoft's signature article warns that VML can make elements show as attachments.
• Logos and images are hosted at a public address, so they load in HTML messages.
• The Copy button puts two versions on the clipboard, HTML and plain text. The plain text version has no images, but your name, title and phone number remain as text, so they still appear in a plain text reply.

To build one, use the free email signature generator. For install steps, see the Outlook guide.

Sources

• Microsoft Support, "Change the message format to HTML, Rich Text Format, or plain text in Outlook": https://support.microsoft.com/en-us/office/change-the-message-format-to-html-rich-text-format-or-plain-text-in-outlook-338a389d-11da-47fe-b693-cf41f792fefa
• Microsoft Support, "Read email messages in plain text in classic Outlook": https://support.microsoft.com/en-us/office/read-email-messages-in-plain-text-16dfe54a-fadc-4261-b2ce-19ad072ed7e3
• Microsoft Support, "Create an email signature": https://support.microsoft.com/en-us/office/create-an-email-signature-31fb24f9-e698-4789-b92a-f0e777f774ca
• Microsoft Q&A, "images in email signature" (May 2021, marked as the same question by 20+ users): https://learn.microsoft.com/en-us/answers/questions/4563392/images-in-email-signature
• Microsoft Q&A, "Signature not showing up in message Reply" (February 2023, marked as the same question by 100+ users): https://learn.microsoft.com/en-us/answers/questions/4597975/signature-not-showing-up-in-message-reply
• Microsoft Q&A, "I have an ongoing issue with the signature image disappearing from when I reply to emails" (April 2024): https://learn.microsoft.com/en-us/answers/questions/4658234/i-have-an-ongoing-issue-with-the-signature-image-d