Sendmail-9 is a new major release of sendmail. It is still under development.
It is a signifficant rewrite of the code base. It will be distributed under "slighlty" modified Licence Agreement.
As far as I know there has been no public "preview" releases so far and you must sign a "Non Disclosure Agreement" before getting the current version.
I have not signed the NDR so do not expect dertailed comments from me.
Current release sendmail-8.13 is publicly available (2004-06-20).