Nor-tech racing email issue

[Carlos69]

I've ordered from them before, great shop to deal with but in attempting to email a quote request (I'm in Oz) yesterday, and today ..
my email is returned as;
"Mail delivery failed
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

[email protected]"
Can anyone suggest how to contact them ? Are they still in business ?

Thanks
Carl