First of All, we must not use the auto-responder system in SFI, If you will use auto-responder it means every time a person will get the same message which shows about you that you are not serious or have no time, always try to use fresh message which will really give motivation and argue others about yourself that you really do care, Now, if you are not available only in this case you can use the auto-responder, which will also put positive impact that you do care...