To automatically forward emails from one email account to another, you use:

The correct answer is Forwarding rule. In email systems, a forwarding rule is a specific setting or instruction that automatically redirects incoming emails from one email account to another designated email address without manual intervention.

• A Filter can sort, move, or delete emails based on criteria, but while it can be part of a forwarding setup, the specific action of sending an email to another address is handled by a forwarding rule.
• Spam settings are used to manage unwanted emails and prevent them from reaching your inbox.
• A Signature is a block of text automatically appended to the end of outgoing emails, not for forwarding incoming ones.