By default, Contact Form 7 has a limit of two distinct mail messages per form, though each can have multiple recipients. This plugin allows you to add as many as you need. It’s relatively simple, so does not include the automatic configuration error detection that the default mails have.
If you only wish to send the same message to multiple recipients, you won’t need this plugin; instead use the To field, or add Cc/Bcc headers in the Additional Headers field as per Contact Form 7’s documentation.
Tested up to v5.9.3 of Contact Form 7.