I forgot that you are in Australia. But I thought that Aurtralia has 02 through 08 area codes. Let me know.

Checking the phone number, it looks like the '043' is an international dialing code for Austria.

See this link:
http://www.datamystic.com/timezone/time_zones.html

It's not a U.S. area code.

Sounds like a phishing scam to me. The address is legit according to the US Postal site. The 'roaming' telephone number country code is from the United Kingdom. You did well in getting more information from them before giving any further information about yourself. They probably would have tried to ...