Hosting for php

I have a contact form which i want to use on a website for a client,

It works fine on my web address hosted by dreamhost, but on his website which is not hosted by dream host the following error comes up

Warning: mail(): SMTP server response: 501 Bad address syntax in
on line 8
Thank you for your interest, your e-mail was sent.

Is this because the host he is using does not support php?