The Sender ID is the mobile number that is displayed on the recipient's cell phone. It's possible to reply to that number by hitting the reply-to button.
My-Cool-SMS supports numeric Sender ID and let's you receive replies directly to your mobile. The EXECUTIVE account also includes text sender id, which can be a company or any word with up to 11 characters.
Please note that the Sender ID feature is currently *not* available when sending to the following countries: Argentina, Belgium, Brazil, China, Colombia, Egypt, France, Hungary, Indonesia, Iraq, Japan, Jordan, Kuwait, Malaysia, Mexico, New Caledonia, Pakistan, Peru, Philippines, Poland, Russian Federation, Saudi Arabia, South Africa, Ukraine, United Arab Emirates. When sending SMS to these countries a random number will be displayed on the target handset instead.