The configured email service can send and receive emails normally on the computer client, but cannot connect using SMTP configuration with WordPress.

    The error message said on your attached image from WP Mail SMTP
    Connection failed. stream_socket_enable_crypto(): Peer certificate CN=YOUR_SMTP_HOST did not match expected CN=mail.YOUR_SMTP_HOST; SMTP server error: QUIT command failed
    In your SMTP Host must be inserted with mail. prefix with your domain name

    Hello, please check whether the domain name of SMTP Host is the domain name certificate used by the mail server domain name?
    Try using None for Encryption, use the domain of the mx record of the domain name for SMTP Host or 127.0.0.1, and use port 25 for SMTP Port. Is it possible to connect?

    aaP_61539618

      Hello, did you use www.xxx.com when adding the domain name MX record to the mail server?
      Try using None for Encryption, SMTP Host or mail.xxxx.dog, and use port 25 for SMTP Port. Is it possible to connect?

      aaP_61539618

      Hello, did you use www.xxx.com when adding the domain name MX record to the mail server?
      Try using None for Encryption, SMTP Host or mail.xxxx.dog, and use port 25 for SMTP Port. Is it possible to connect?

      aaP_61539618