Email notifications "Failed to send the email: EOF"

I’m using the web UI.
I’m trying to configure Duplicacy to send emails.
I’ve set up an account on Sendgrid and entered the details into the email notifications dialog. When I click “test”, seemingly nothing happens. When I check the log, ~5 minutes later an entry appears with the message “Failed to send the email: EOF”.

Any suggestions?

Thanks

The EOF error means the server closed the connection. Can you make sure that the server name and port are correct?