Loopback IP address

I am suddenly getting a mess of spam emails. I have been doing a little whois in the headers but have found several that are using a loopback address. Is this a way of hiding who they are?

Last login: Tue Nov 10 06:52:51 on ttys000

% whois 127.0.0.1

% IANA WHOIS server

% for more information on IANA, visit http://www.iana.org

% This query returned 1 object

inetnum: 127.0.0.0 - 127.255.255.255

organisation: IANA - Loopback

status: RESERVED

remarks: 127.0.0.0/8 reserved for Loopback [RFC1122], section

remarks: 3.2.1.3. Reserved by protocol. For authoritative

remarks: registration, seeiana-ipv4-special-registry.

changed: 1981-09

source: IANA