[BlueOnyx:23479] 5209R mail issue

[Larry Smith]

having an issue suddenly today with a 5209R (build 20191117).  
Server has been working fine for several days but after last 
nights updates is delivering mail to users mbox instead of the
configured Maildir setup (which was working).

Any clues on where to look to resolve this before I get tar and feathered?

(my changes to /etc/dovecot/conf.d/10-mail.conf still appear to be there
and my changes to /etc/mail/sendmail.mc (enabling procmail) are still
there.)

-- 
Larry Smith
lesmith at ecsis.net