I upgraded Yosemite 10.10.5 to El-Capitan over the last 2 days, and also disabled SIP. .. and because I do a lot of building of my own things like postfix and dovecot, I didn't notice until today that I no longer have a root user, and where 'root' should appear, it's ownership is now 'dovenull' - a user name related to dovecot. I wonder what happened to 'root' ?
drwxrwxr-x+ 152 dovenull admin 5168 6 Oct 12:32 Applications
drwxr-xr-x+ 64 dovenull wheel 2176 5 Oct 21:59 Library
drwxr-xr-x@ 2 dovenull wheel 68 5 Oct 21:51 Network
drwxr-xr-x@ 3 robert staff 102 8 Sep 21:18 Read Before You Install iTunes.app
drwxr-xr-x@ 4 dovenull wheel 136 5 Oct 21:45 System
lrwxr-xr-x 1 dovenull wheel 49 21 Feb 2015 User Information -> /Library/Documentation/User Information.localized
drwxr-xr-x 15 dovenull admin 510 5 Oct 21:51 Users
drwxrwxrwt@ 7 dovenull admin 238 6 Oct 14:31 Volumes
Everything appears to work fine, including the mailserver and apps. Should I worry about this?