sendmail errors upon partial upgrade

[Jeffrey Bouquet]

gateway sm-mta[1533]: NOQUEUE: SYSERR(root):
opendaemonsocket: daemon Daemon0: cannot find: Can't assign requested address
gateway sm-mta[1533]: daemon Daemon0: problem creating SMTP socket

root is not getting any usual emails.
I tried mergemaster again, same result
service sendmail start; stop; start

still nothing.

Web searches turned up the term but in only a few posts and in edge cases not particularly
FreeBSD...

Not that the root emails are all that important in the short term but I'd like them resumed if at all possible
without a full buildworld cycle...