mail server unable working

[pudding1111]

aapanel 6.8.31
mail server 406
Add SSL unable working,
When applying for SSL, the certificate and secret key will be displayed, but there is no response when clicking on save. I watched youtube and others will display the certificate expiration time here, but I did not.
When adding an SMTP email, an error will be reported
stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed