Sendmail 8.8.8 and sendmail 8.9 are considered current. An upgrade is recommended, but not urgent as major differences relate to security issues for users who have legitimate access to the machine already. I.e. sendmail version 8.8.7 may permit a non-privledged user with access to the firewall shell to obtain super user priveledges. As no such non-privledged users should exist, this is not a large problem.