Error when sending email

This happens every time I tried to send an email by "Execute locally" but it works fine when using agent. I have attached part of the log where the error is shown, it is the same error every time. Please advise

What if you temporary stop the agent and try to send email.
Does it work?

I'm going to run some tests and get back to you, But I feel it is the connection/encryption type

Status update from the customer

"I was right , I had to change encryption to implicit instead of explicit and it works now"