Mail — 6 steps, ~2 minutes

Copy button included below

1
Open the Mail app and click the gear icon in the bottom-left corner to open Settings.
2
Click Signature.
3
Choose the account this signature is for from the dropdown, or check "Apply to all accounts."
4
Turn on the "Use an email signature" toggle.
5
Click into the text box and paste your signature.
Make your signature first →
6
Click Save.

Good to know

Microsoft ended support for the Windows Mail app on December 31, 2024. It still opens, but it can no longer send or receive email, so a signature set here won't actually go out on anything. If you're composing and sending mail on Windows, set your signature up in new Outlook instead — see our Outlook (new) guide.
Even before that, Mail's signature box only ever accepted plain text — no bold, colors, links, or images — so your logo and formatting wouldn't have survived a paste here regardless.
New Outlook uses a completely separate settings screen, so nothing you set up here carries over automatically; you'll need to add your signature again there.