Can we Discard these existing Test Cases 
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* serial number of the form YYYYMMDDnn
   * Reasons for not discarding : The recommended syntax is YYYYMMDDnn (YYYY=year, MM=month, DD=day, nn=revision number.  This would not overflow until the year 4294. (RFC 1912 [page 3]) 
   * Reasons for discarding : Even though some BIND versions allow you to use a decimal in a serial
   number, don't.  A decimal serial number is converted to an unsigned 32-bit integer internally anyway.  The formula for a n.m serial number is n*10^(3+int(0.9+log10(m))) + m which translates to 
   something rather unexpected.  For example it's routinely possible with a decimal serial number (perhaps automatically generated by SCCS) to be incremented such that it is numerically larger, but after the above conversion yield a serial number which is LOWER than before.  Decimal serial numbers have been officially deprecated in recent BIND versions. (RFC 1912 [page 3])
* Delegated domain is not an openrelay
   * Reasons for discarding : Not required for testing DNS
* Domain of the hostmaster email is not an openrelay
   * Reasons for discarding : Not required for testing DNS
* Can deliver email to 'postmaster'
   * Reasons for discarding : This test conforms to the requirements in RFC 1123 [Page 52] "A host that supports a receiver-SMTP MUST support the reserved mailbox "Postmaster"". The RFC is setting up the
requirements for Internet hosts. But this test requirements is not really the responsibility of DNS. D
o we need this ?

* Can deliver email to hostmaster
   * Reasons for not discarding : It is imperative that this address get to one or more real persons, because it is often used for everything from reporting bad DNS data to reporting security incidents (RFC 1912 [page 3]) 

* Domain able to receive email (delivery using MX, A, AAAA)
   * Reasons for discarding : Not required for testing DNS
* Test if mail delivery possible
   * Reasons for discarding : Not required for testing DNS

Defining the Test Cases
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* ICMP answer
* root servers list present
* root servers list identical to ICANN
* root servers addresses identical to ICANN
* coherence between NS and ANY records
* coherence between SOA and ANY records
* coherence between MX and ANY records