kalob3: SPF record?

[Johannes Graumann]

Hello,

I have been testing a kolab3/Debian wheezy set up using 
http://www.allaboutspam.com/email-server-test

One of the comments that comes back is:
> <MYDOMAIN>.org> does not have any SPF records set. Using SPF
> minimizes the chances of your Email being rejected or be classified as
> SPAM. Ideally, the SPF records for <MYDOMAIN> must return 'pass' for your
> Email server IP <MYIP>. For more details on publishing SPF records for
> your domain, please refer to http://old.openspf.org/wizard.html

Aside from the fact that the facility referred to is dead ... is this worth 
implementing? And if so: what might an implementation (preferably on Debian) 
look like and consist from?

Thanks for your input.

Sincerely, Joh