Dear Attorney,

I am on vacation but have received word from the board member who is checking our mail that xxx’s H1B visa petition was approved.  Congratulations.  I don’t know exactly what you ended up writing, but apparently it did the job, and rather quickly.  I was initially discouraged by all of the objections that immigration voiced, but through your skill, they were apparently overcome. 

Thank you very much for your help.  It really made a big difference in xxx’s life, not to mention her baby. 
Best Regards,

p.s. I would definitely refer other clients to you and your firm

(Director of the client’s employer)