message 'Could not instantiate mail function.'

I've setup a Joomla 1.6 page with HikaShop for an online store.
I'm testing it now localy and it runs fine, but when I start shopping and add some items in the basket, I get the message 'Could not instantiate mail function.' at the end when I checkoout.
The order is processed well, but where can I setup the mailfunction and how ?

Email configuration is global to your website. You should configure them in the configuration of Joomla.

Hello:
I am experiencing the same issue and do not understand your proposed solution. What exactly do I have to reconfigure in the global settings of my joomla installation to take care of the error message?

Thank you

In the global configuration of joomla, under the server tab, you have a zone where you can configure your email settings:
help.joomla.org/content/view/1445/196/
Once you configured them accordingly to your hosting recommendations, that message should not appear anymore and the emails should be sent.