Missing e-mail address of sender

Hi there,

could you please advise me a solution of an issue?
When a page visitors sends a message to my client through Contact Form 7, he receives the message, the sender’s name, but can’t see the sender’s e-mail and so is unable to answer!
Do you know where is the problem?
Thank you very much!

Kind Regards
Jirina

The page I need help with: [log in to see the link]