By setting contact field backup instructions, Maileon is told to backup the values of indicated contact fields used in mailings and to map them to the mailings. This feature is expensive in terms of storage and should only be used for those contact fields that are expected to be frequently updated and that are relevant for reports.
Authorization: Basic XXXXXXXXXXXXXXX
Content-Type: application/vnd.maileon.api+xml; charset=utf-8
<!-- indicates the type of the contact field. Supported values are:
"standard" and "custom" (custom contact fields)
<!-- name of the contact field -->