From enail address not showing in emails received

When I receive an email from my site all of the senders text is OK except that the senders email email address is missing.

Have checked the set up and it appears as it does on the form on the site.
<p>Your Email (required)
[email* your-email] </p>

Can any one help please.

I keep getting email contacts without knowing who to reply to.

Thanks
Chris

https://wordpress.org/plugins/contact-form-7/