Issues with SMTP settings e-Newsletter Plugin

Hi there,

I've installed the e-Newsletter plugin and am using 1and1 for my email.

I have put in the following settings:

From email: info@heartofsuffolk.co.uk
SMTP Outgoing Server: auth.smtp.1and1.co.uk
SMTP Username: info@heartofsuffolk.co.uk
SMTP Password: (password as set up on 1and1)
SMTP Port: 25

After clicking Test Connection I got an error message. Can you tell me where I might have gone wrong?