Unfortunately, this has become a trend for almost all apps and services - to promote themselves.

Enable it if you want to have the same signature for all accounts connected to the Mail app. Under the accounts drop box, there is an option called 'Apply to all accounts'. It is worth mentioning that you can specify the same signature for all accounts you have. For example, you can type something like 'Best regards, John Smith' in the text box below the switch.

Alternatively, you can specify a new signature.

If you disable it, the signature will be disabled for the selected account. There see the option Use an email signature.

The signature page of options will be opened.

In the Mail app, click the gear icon to open its Settings pane.

Tip: Save your time and use the alphabet navigation to quickly get to the Mail app. To disable the Sent from Mail for Windows 10 signature, you need to do the following. By default, the app uses a pre-defined signature for all outgoing e-mail messages, but you can disable or change it. It supports multiple accounts, comes with preset settings to quickly add mail accounts from popular services, and includes all the essential functionality to read, send and receive emails. The app is intended to provide basic email functionality to Windows 10 users. Windows 10 comes with a Universal app, 'Mail'.

Sent from mail for windows 10