wal-land.cn.		30 IN SOA . hostmaster.nameserver. (
				29         ; serial
				28800      ; refresh (8 hours)
				7200       ; retry (2 hours)
				604800     ; expire (1 week)
				5          ; minimum (5 seconds)
				)

Mail exchangers:
wal-land.cn.		30 IN MX 10 mail.wal-land.cn.