fd6cdfac_ate__RA_API____Dyn_Help_Center__Description
[Field] backmx [Additional Info] YES activates preferred MX record pointed to hostname itself, NOCHG keeps the previous value, any other value is considered as NO and deactivates the corresponding DNS record. Parameter is ignored for situations when no MX value is set for host and for Dyn Standard DNS hosts. [Description] 
Requests the MX in the previous parameter to be set up as a backup MX by listing the host itself as an MX with a lower preference value. (Deprecated: Flag is currently ignored)
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Description