Type: path
Default: ""
This variable specifies the file where the certificates you trust are saved. When an unknown certificate is encountered, you are asked if you accept it or not. If you accept it, the certificate can also be saved in this file and further connections are automatically accepted.
You can also manually add CA certificates in this file. Any server certificate that is signed with one of these CA certificates are also automatically accepted.
Example: set certificate_file=~/.mutt/certificates