Running Sendmail with Sender Policy Framework

My experience in getting SPF milter to run on Sendmail is recapped below:

1. Check sendmail package already has MILTER plugin compiled:
# sendmail -d0.1 -bt < /dev/null grep MILTER
2. Get libspf2 rpm and install by rpm -ivh;
3. Get spfmilter rpm and install by rpm -ivh;
4. Add the following in sendmail.mc
INPUT_MAIL_FILTER(`spfmilter', `S=unix:/var/run/spfmilter.sock, T=S:4m;R:4m')
5. Rebuild sendmail.cf;
6. Run #spfmilter unix:/var/run/spfmilter.sock
7. re-start sendmail


A chart of IPv4 allocation

This is an interesting chart.

Do you believe we still have 25 % unicast resources remaining ?