Click on the "Invoicing" tab to bring up the list of options and then select "Send Invoices by E-mail", followed by "Send E-Mails".
You will then see the following information screen.
If you are happy to continue then click on "OK", otherwise click "Close" to cancel. When you click on "OK" you will then be asked to confirm that you want to continue with sending out the emails.
Click on "Yes" to proceed or "No" to cancel. Once you have clicked on "Yes", the process of sending out the emails begins, as each email is sent you will see a confirmation screen.
Click on "OK" and repeat until all emails have been sent. When all the emails have been processed you will see the following screen.