Why Is My Email Signature Image Showing as an Attachment? How to Fix It

The paperclip problem, explained

You added a logo or headshot to your email signature, sent a test message, and something looks off: there is a paperclip icon on the email, and your image shows up as an attached file rather than sitting neatly in the signature. It is one of the most common — and most confusing — email signature issues, and once you understand why it happens, the fix is straightforward.

Why it happens: embedded vs hosted images

There are two fundamentally different ways an image can appear in an email, and the difference is the whole story.

• Embedded (inline) images are attached to the message itself and displayed using an internal reference. The image data travels inside every email you send. Because the file is genuinely attached, many email clients — Outlook in particular — show a paperclip and list the image as an attachment.
• Hosted (linked) images live on a public web server. Your signature simply points to the image's web address, and the email client fetches it when the message is opened — exactly like an image on a web page. Nothing is attached, so there is no paperclip.

When you drag an image into the signature editor, or paste it in, most desktop clients embed it. That is why your carefully placed logo turns into an attachment.

Why Outlook is the usual culprit

Outlook has long embedded signature images as inline attachments by default. Even though the image is meant to display within the message, Outlook still flags the message as having an attachment, so recipients see the paperclip. Gmail and Apple Mail handle this more gracefully in some cases, but the underlying issue — an attached image file — is the same.

The fix: host the image and link to it

The reliable solution is to stop embedding the image and start linking to a hosted copy instead. In practice:

1. Upload your logo or headshot to a public URL — your website, an image host, or a signature service. You need a stable https address that anyone can load.
2. Reference that URL in your signature using an image tag whose source is the hosted address, rather than pasting the raw image file.
3. Rebuild the signature in your email client using this linked version, replacing the old embedded one.

Now the image loads from the web on demand. There is no file riding along with the message, so no paperclip and no attachment.

Why not just paste in a Base64 image?

Some guides suggest embedding the image directly in the HTML as a Base64 data string. Avoid this. Several major clients — Gmail among them — strip out Base64 images entirely, leaving your recipients with a broken-image box. Hosted URLs are the only method that works consistently across Outlook, Gmail and Apple Mail.

The rule of thumb: if the image travels with the email, it becomes an attachment. If the email points to an image on the web, it does not.

Client-by-client notes

Outlook (desktop)

Rebuild your signature under File, Options, Mail, Signatures. When you insert your logo, make sure you are inserting a linked image, not a local file. A signature built from hosted HTML pasted into the editor avoids the embed behaviour.

Gmail

Gmail's signature editor does not let you attach images from your computer; it expects an image that is already hosted on the web. This actually protects you — paste in a signature whose image points to a URL and you are done.

Apple Mail

Apple Mail can embed dragged-in images too. Build the signature from hosted HTML and, in signature preferences, keep the "always match my default message font" option unchecked so your formatting survives.

The easiest way to avoid it entirely

The whole class of problem disappears when your signature is generated with hosted images from the start. That is how Sigmint works: your logo and any icons are served from public URLs and referenced by link, never embedded, so nothing arrives as an attachment and nothing triggers a paperclip. The templates are tested against Outlook, Gmail and Apple Mail, so the image shows up where it should. You can build a signature, add your logo, and copy a version that is already correctly linked.

If you are staring at a stray paperclip right now, this is the fix: stop embedding, start hosting, and rebuild the signature once. Every email after that will look the way you intended.