Does appliance Call Home only use eth0, and does it use SMTP?

I understand that appliance call home needs access to:  http:// www.symappmon.com

...and this tech note describes how to troubleshoot Call Home:

http://www.symantec.com/business/support/index?page=content&id=TECH152748

A couple of questions if I may:

1) I've read somewhere that Call Home uses NIC1/eth0 only.  Is this true?

2) Does Call Home also perform any activity via SMTP?

Thanks.