This refers to a mail server that accepts mail from any sending host. Accepts All is a regular feature for business email addresses and a few personal addresses. These addresses are usually a prominent feature of a spam trap, are called catch-all in this case.
Catch-all, also known as “accept-all” is a domain-wide setting mail server that is configured to accept all emails sent to the domain, no matter if the specified mailbox exists or not.
A catch-all email account is an address specified for receiving all messages addressed to a domain’s incorrect email address. For example, you have three email addresses set up for coolexample.com; [email protected], [email protected], and [email protected]; as a catch-all email account, you can set up [email protected] Any email messages sent to [email protected] (or any other invalid email address) will then be sent to the [email protected] account. There is no definite way to determine if this email is valid or invalid. You can find more information here: What is a Catch-all or Accept-all Email?