Email at HG but website at weebly?

I have a customer who want me to change DNS A records to point his domain to a weebly site his son made for him, but he wants to keep his email as is. I change the A records for www.hissitename.com and hissitename.com to the weebly IP, but when I updated it I get the following message I did not change nameservers or mail IP's and the domain does resolve to the weebly site.
I sent a test email and sure enough it did not get to the customers email box on my server.

Is what he wants even possible? If so, any help would be appreciated.

Thanks