The sendmail binary in /usr/sbin of rpm sendmail-8.11.6-15 should just be called "sendmail", but somehow it got spelled as "sendmail.sendmail" and all of sudden all programs including logging programs can no longer send mail. An easy workaround in the interim is to "sendmail" a symlink to the real sendmail.
This is using the new "alternatives" support in Red Hat Linux 7.3 to have a selection between multiple MTAs. greetings, Florian La Roche