Open Foxmail and click "Tools-Account Management" in the menu bar.

In the pop-up interface, select the email account to which you want to add a signature file on the left, and click Signature Management to start setting up.

In the signature management interface, click New directly, and then a small box will pop up, where you can name the signature file for easy management in the future.

In the new signature box, enter the signature you set. In the following options, you can also confirm which email address the entered signature is used for. You can also insert pictures into the signature.

After setting the signature, click to write the email. After writing the body, click "Insert" - "Signature" and select the signature you just set to insert it.