rescuing mail server

The Hong Kong National Education Centre (HKNEC) has been under DDoS attack by Anonymous since last Saturday and the attack is going on.  Both web access and email service can not respond.  From DNS records, I note that there are some actions taking place to rescue the mail service:

hknec.org.              3600    IN      MX      90 218.103.29.37.

hknec.org.              3600    IN      MX      10 mail.hknec.org.

HKNEC wants to use the backup mail server to rescue in case the main can not respond.  However MX can not point to an IP address.  "218.103.29.37. " is wrong with a full stop after 37.  For host name, the last full stop is required.

Another thing wrong is that the backup mail server (218.103.29.37)  and the main server (218.103.29.36) are on the same network segment and the network segment is now under heavy DDoS traffic.  An IP address outside the network segment should be used for mail backup.

Don't laugh...  I have learnt a lot from the rescue operation of HKNEC.