Yes Hainzy it is the big free ones like hotmail, yahoo, gmail etc.
Correct your work email addresses are not affected.

People will need to register with their ISP (Internet Service Providers) email address such as;

joebloggs@bigpond.com
joebloggs@iinet.com
joebloggs@internode.net
joebloggs@tpg.com.au
joebloggs@bhp.com.au