I am using MailKit library to send emails. However the below error keeps on showing

MailKit.Security.SslHandshakeException: An error occurred while attempting to establish an SSL or TLS connection.

I am using Nginx web server and have changed ssl protocols to support TLS 1.2 and TLS 1.3 and checked that both protocols are enabled via SSLLabs test. However on the smtp client logs (which supports TLS 1.2) it shows that the handshake has been done via TLS 1.0 as in this snapshot