SMSServer is a shareware software, the trial version is complete of all the features and it is valid 30 days from first installation. When trial period expires, you can purchase a permanent license directly from the section Buy of this website. In order to read CHM files it is possible that your operating system will require an authorization.
If you can't read anything after opening the CHM guide right click the file you downloaded, select "Properties" and then press the pushbutton "Unblock" on the bottom - right side of the "General" Tab.
To request the newest copy of SMSServer just login or register, the registration is free and just asks your name and a valid email where we can contact you in case of critical update of SMSServer.