Theplanet, please update rhn-proxy01.dllstx2. I don't care about other rhn satellites, that's the one I use. Thanks.

All of the rhn servers should have this update. Try:

rpm -q --last sendmail


[root@planetx fme]# rpm -q --last sendmail
sendmail-8.12.11-4.RHEL3.4 Wed 22 Mar 2006 05:01:48 PM CST

.4 is the release that RedHat applied the fix to.

More information here:

https://rhn.redhat.com/errata/RHSA-2006-0264.html

I've tried it on the 22nd. No updates then.
It was updated on 23rd at about 18:00 GMT+01