Dear Felix
I would like to thank you for suggesting [NAME, ex. Joseph Johnson] for our [STATE POSITION, ex. Sales Manager] position. [STATE WHAT HAS TRANSPIRED AS A RESULT OF SUGGESTION, ex. Joseph will be coming to our office on Friday for an interview. I am indeed impressed with his resume.]
Thanks again for your recommendation. I will keep you informed and up to date on what transpires.
Regards
Lydia