Anything obviously wrong with this DNS Configuration?

Just upgraded to OS X Mavericks and Server 3.1.2 and suddenly I have a problem with mail (sending but not receiving) and this (which I've obviously got to resolve first)...

sh-3.2# changeip -checkhostname

Primary address = 192.168.0.104

Current HostName = server.example.com

The DNS hostname is not available, please repair DNS and re-run this tool.

dirserv:success = "success"

==============================================================================

/Library/Server/named/db.example.com

example.com. 10800 IN SOA example.com. dnsadmin.example.com. (

2014053009

20864

3600

14976

10800)

10800 IN NS server.example.com.

10800 IN MX 10 mail.example.com.

_http._tcp.example.com. 10800 IN PTR Web._http._tcp.example.com.

Web._http._tcp.example.com. 10800 IN SRV 0 0 80 server.example.com.

mail.example.com. 10800 IN CNAME server.example.com.

ns1.example.com. 10800 IN CNAME server.example.com.

server.example.com. 10800 IN A 192.168.0.104

==============================================================================

/Library/Server/named/db.0.168.192.in-addr.arpa

0.168.192.in-addr.arpa. 10800 IN SOA 0.168.192.in-addr.arpa. admin.0.168.192.in-addr.arpa. (

2014052907

86400

3600

604800

345600)

10800 IN NS ns1.example.com.

10800 IN NS mail.example.com.

10800 IN NS server.example.com.

104.0.168.192.in-addr.arpa. 10800 IN PTR server.example.com.

==============================================================================

It's a very straightforward configuration where everything is forwarded to/from my mac mini (called "server") via my Airport Extreme. Server hosts the website, mail server and nameserver.