Round Robin and "MX" type records

[Luiz, Dave@HWDC]

Hello DNS Folks!
I received a request today to implement "round-robin" load sharing on
selected MX records soon to be in my DNS. I have done the "round-robin"
thing before using "A" and CNAME" records, but never using the "MX" record
type. Although I could have overlooked it, I have yet to see this activity
referenced in any RFC, FAQ or newsgroup as it pertains to MX records.
However, the "DNS and BIND" O'Reilly book (2nd edition, pg 212) states "(In
fact, the name server will rotate any type of record, not just address
records, as long as a given domain name has more than one of them.)"

My questions are:
1. Is this a feasible way to do informal load sharing across multiple Mail
Exchanger hosts? 
2. Does it violate any standards?
   

We are using bind4.9.3 on AIX 4.2.1 and I envision the following:
myemail.domain.gov                     3600 IN  MX  0
mailserver1.domain.gov
myemail.domain.gov                     3600 IN  MX  0
mailserver2.domain.gov.

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Dave Luiz - Network Management Unit 
State of California - Health and Welfare Data Center
Phone: (916)-739-7703                
Fax: (916)-454-7232                  www
mailto:dluiz at hwdc.state.ca.us       (@ @)    
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