The Windows 10 Mail app is a decent email client that allows you to add other email accounts in addition to your Microsoft accounts. You’ll notice, though, that any emails you write in the Mail app have a default signature.
Microsoft assumes you want to tell everyone that you’re using their Mail app by adding a “Sent from Mail for Windows 10” signature to all your emails, even non-Microsoft accounts. If you’d rather use a custom signature or no signature at all, it’s easy to change or disable the signature for each account.
To begin, open the Mail app and click the Settings gear icon on the vertical toolbar in the lower-left corner of the window.
On the Settings pane that slides out on the right, click the “Signature” option.
The Signature pane displays on the right, with options for setting or disabling the signature. You can do this separately for each account or for all accounts at once. Select the account for which you want to change or disable the signature from the “Select an account” drop-down list.
If you want to use the same signature for all accounts in Mail, check the “Apply to all account” box.
To disable the signature for the selected account or all accounts, click the “Use an email signature” slider button so if says Off.
To use a custom signature in the selected account or all accounts, enter text in the box below the Use an email signature slider button. You can enter multiple lines of text, but you can’t add hyperlinks, change the font or font color, or add images. Click anywhere to the left of the Signature pane to close it.
NOTE: The default signature in Mail contains a link on the word Mail that takes you to the Mail app’s page on the Microsoft Store. If you replace the default signature with your own text, you will lose that link, even if you enter the default message again, because you can’t add hyperlinks.
Now, when you create a new email message by clicking “New mail” on the left panel…
…you’ll see your new signature automatically added to the new message, or no signature at all, if you disabled it.
If you are currently composing a new email or a reply/forward when you change your signature, the signature in that email will not change to the new signature or be deleted if you disabled the signature. The same is true for drafts you have saved.