I used to use one called Auto SMS System and it was working very well for me but for some reason the whole system stopped working and even the site was down and I could't find any other system that does what this does. I did searched online but didn't find anything good or they charge for each SMS you send out and I don't want that. I was just using a smtp to send out message to mobile numbers and also have a delay feature so your mail server won't raise a red flag. Hope someone can help me. Thanks.