How to add a signature in Outlook for Mac
Add or change your email signature in Outlook for Mac and legacy Outlook for Mac, set it for each account, and fix images and double-spaced lines.
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If you already have a signature, copy it and follow the steps below. If you need one, make it free on Signatoro, then click "Copy signature".
These steps are for the Outlook app on macOS. Apple's own Mail app has its own Apple Mail guide.
Add a signature in Outlook for Mac
To add a signature in Outlook for Mac:
- On the "Outlook" menu, select "Settings", then under "Mail" select "Signatures".
- Select the plus button to add a signature, and type a name.
- Paste the signature into the signature editor.
- Under "Choose which signature appears", select your account and set "For new messages" and "For replies or forwards".
- Close the Signatures window.
Change your Outlook for Mac signature
To change a signature in Outlook for Mac, select "Settings" on the "Outlook" menu, then "Signatures" under "Mail". Under "Signature name", select the signature and select "Edit". Delete what is in the editor, paste the new signature, and close the Signatures window.
Add a signature in legacy Outlook for Mac
Legacy Outlook for Mac adds signatures through "Outlook" > "Settings" > "Signatures" too, with older labels: "Signatures" sits under "Email", the ready-made signature is called "Untitled", and the defaults are set under "Choose default signature" in "New messages" and "Replies/forwards". Microsoft says support for legacy Outlook for Mac ends in October 2026.
Outlook for Mac signature questions
Why won't Outlook for Mac add my signature automatically?
Outlook for Mac adds a signature automatically only after it is chosen for the account under "Choose which signature appears" in Settings > "Signatures", in "For new messages" and "For replies or forwards". Users on Microsoft's Q&A forum reported in April 2026 that version 16.108 reset the choice to "None" on closing; updating Outlook for Mac and choosing the signature again is the reported fix.
Can I have a different signature for each account in Outlook for Mac?
Outlook for Mac sets the default signature separately for each account. In Settings > "Signatures", under "Choose which signature appears", select an account and pick its signatures for "For new messages" and "For replies or forwards", then select the next account and repeat. An account left without a choice sends mail with no signature.
Why can't I add an image to my Outlook for Mac signature?
Outlook for Mac adds pictures to a signature from the signature editor in Settings > "Signatures", through "See more items". Users on Microsoft's Q&A forum reported in April 2026 that the picture option was grayed out in version 16.107.4 and came back in 16.108, so update Outlook for Mac to the latest version before adding the image again.
Why is my Outlook for Mac signature double spaced?
An Outlook for Mac signature looks double spaced when each line is its own paragraph. Users on Microsoft's Q&A forum and Reddit reported the spacing changing after Outlook for Mac updates in early 2026, and the fix they report is to delete the line breaks in the signature editor and retype them with Shift+Return, which keeps the lines in one paragraph.
For agents
If you're an assistant setting this up on someone's behalf: these are the "Outlook" > "Settings" > "Signatures" steps, in order, on macOS. Setting the account's default under "Choose which signature appears" matters: a signature that exists but is not chosen for the account is never inserted. Paste the signature as formatted text, do not reformat it.
Sources
Checked against Microsoft's own help pages on 2026-09-25:
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