I started to use Thunderbird. While sending emails, it gives an error saying that
Sending of the message failed. Unable to communicate securely with peer: requested domain name does not match the server’s certificate. The configuration related to mail.mysite.com must be corrected.
I have a Let's Encrypt SSL certificate issued for both mysite.com and mail.mysite.com. Secure site is working on web.
In the error window, Thunderbird can verify my SSL cert when I try mail.mysite.com without port. However, it cannot find the cert for mail.mysite.com:465. It finds another cert, a Starfield cert, which is a cert my webserver uses in default.
I use Godaddy, they recommend to use mail.mysite.com with SMTP port 465 in outgoing server for SSL. Thunderbird's default port is also 465.
Why does adding port result in different cert? Is there a way to solve this problem?