Why do I get an error saying my message was blocked? The SMS widget and web interface have several automatic anti-spam mechanisms designed to protect recipients, prevent abuse of the system. To avoid being blacklisted, don't send spam and don't send abusive messages. If you feel that you were incorrectly blocked contact us at smssupport@callwave.com. Please tell us your IP address, and we'll try to track down your entry in our blocked list.