While working with one client I was getting below error in DNS

DNS error bad owner name (check-names) /tmp/cpanel

So I went ahead and checked DNS zone file using below command

root@vps [/var/named]# named-checkzone onlinecsource.com /var/named/onlinesource.com.db
/var/named/onlinesource.com.db:56: _autodiscover._tcp.cheapsalesleads.onlinesource.com: bad owner name (check-names)
/var/named/onlinesource.com.db:57: _autodiscover._tcp.cheapsalesleads.onlinesource.com: bad owner name (check-names)
zone onlinesource.com/IN: loaded serial 2017030209
OK

So the error pointed to line 56 and 57 in zone file

Went ahead and deleted the line 56 and 57 and reload DNS zone file

All works good now