Firstly, you need to register your email address for Vodacom email to SMS by visiting https://www.email2sms.vodacom.co.za
You will receive an email with a link that you need to click in order to confirm your email address so that you can send email to SMS.
Once you have confirmed your email address you will be able to send Vodacom email to SMS by sending email to firstname.lastname@example.org (e.g. email@example.com). Leave the subject line empty, and don't exceed 140 characters in the body of the email (remove your signature).
An error notification email will be sent to you if you exceed your quota of 3 SMS per day. You can also send Vodacom email to SMS from Free082SMS.