How to add an email signature in Apple Mail

Before you start: have the signature ready

Mail's signature box is a rich-text editor, not an HTML editor, so you cannot paste code into it. Build the signature elsewhere, copy it as formatted text and paste the result. The free signature generator does this: it puts rich text on the clipboard with the Copy signature button and the layout survives the paste.

Mail on a Mac

1. Copy your signature.
2. Open Mail → Settings (⌘+,) and click Signatures.
3. In the left column, select the account the signature is for. Selecting All Signatures creates one you can drag onto an account later.
4. Click + and give the signature a name.
5. Untick Always match my default message font. With it ticked, Mail throws away the fonts, sizes and colors you paste.
6. Click into the box on the right, select the placeholder text and paste (⌘+V).
7. At the bottom, set Choose Signature to the new one so it is the default for that account.

Close the window and Mail saves it. Start a new message to check the result; you can switch between signatures from the Signature pop-up menu in the compose window.

Mail on iPhone and iPad

The iOS and iPadOS Mail app keeps its own signature and the box is plain text: no logo, no colors, no links beyond what iOS auto-detects. Whatever is set on the Mac does not sync down.

1. Open Settings, scroll to Apps → Mail (on older versions, Mail is directly in Settings).
2. Tap Signature.
3. Choose Per Account if you want a different one for work and personal.
4. Type name, title, company and phone on separate lines. Keep it to four or five lines.

The paste trick. If you paste rich text into the box and then shake the phone and tap Undo Change Attributes, iOS keeps the layout and images once. It is fragile: it breaks on the next iOS update and the images are attachments, not hosted files. Most organizations stop fighting it and apply the signature server-side instead; see the phone signature guide for what that involves.

Common problems

The fonts and colors vanished after pasting

Always match my default message font is still ticked. Untick it, delete the signature and paste again.

The logo shows as a question mark or a blank box

Mail displays images that are hosted at a web address and images that were embedded when you pasted. A logo dragged from Finder is usually embedded as an attachment, which recipients on Outlook see as a paperclip. Use a logo hosted on your website, which the generator's link to a logo option does.

The signature appears twice, or on replies but not new messages

Mail adds the signature once per account. If you also have a signature set in an Exchange or Gmail account's own settings, both appear. Remove one. Placement above or below the quoted text is under Settings → Composing.

It sits on a white block in dark mode

The pasted HTML carries a background color. Re-copy from a source with no background, or export the logo with a transparent background so only the image sits on white.

Different signature on another Mac

Signatures sync between Macs through iCloud Drive when Mail is enabled under iCloud settings. They never sync to iPhone or iPad, and they do not sync to Outlook or Gmail on the web.

Setting signatures for a whole company

Apple Mail is the client where the per-device problem is worst: every Mac keeps its own copy and every iPhone keeps a plain-text one. UnifySig sidesteps the client entirely by adding the signature as mail leaves Microsoft 365 or Google Workspace, so a message sent from Mail on an iPhone carries the same signature as one sent from Outlook on Windows.