1st, change your Outgoing mail server (SMTP) to mailauth.totalweb.net.uk

2nd, select the option for My outgoing server (SMTP) requires authentication
         The credentials will be the same as those to access your POP mailbox.

Finally, set the Outgoing server (SMTP) port to 587

You should then be able to send email via the authenticated server.

In addition you may want to send using an encrypted connection (SSL). This option is supported on the server but may not be by your mail client or possibly your antivirus/firewall.

Example screen shots from Outlook Express 6 showing the changes above.