18.104.22.168.1 Setting Send on Behalf Permissions
The delegator's client SHOULD grant send on behalfpermission to every delegate and stop creating a delegation relationship if send on behalf permissions cannot be granted. Granting send on behalf permissions is accomplished by adding the value of the PidTagEntryId property ([MS-OXCPERM] section 2.2.4) of the delegate's Address Book object to the PidTagAddressBookPublicDelegates property ([MS-OXOABK] section 22.214.171.124) of the delegator's Address Book object. This value is added by using the NspiModLinkAtt method, as specified in [MS-NSPI].
A client SHOULD<3> support delegation for a remote user (1) if the remote user (1) indicates that it supports sharing of the delegator's information. The remote user (1) supports sharing of the delegator's information if the remote user's (1) Address Book object has bit S set in the PidTagDisplayTypeEx property ([MS-OXOABK] section 126.96.36.199).