So you're saying that you're not receiving any emails ?
Are you receiving Joomla emails ? (you can test with the mass email feature of joomla).
If you don't receive joomla emails either, it means that you didn't configure the emails options of joomla properly in the joomla configuration. You should ask your hosting company what settings to use in there.
If you receive the joomla emails but not hikashop's, then it means that you have a problem with the settings in the email tab of the configuration of HikaShop. Again, you should ask your hosting company what settings to use in there (for the right side of that option tab)