Actually you do that with any email client including outlook as that is not really related to the email client you're using. What you need to do is use an
SMS gateway which will allow you to send an email and have it received as an SMS.
You would email your text message to the gateway via something like this: PhoneNumber@SMSGatewayName in the recipient and fill the title and body with whatever text you want to send. As far as I know most gateways are commercial(if not all) and I am not sure about those available for Lebanon. Hope that helps.