The following Free/Busy error is received:
"<F/B Receiver> (37995) Packet processing from Packet Queue failed. Packet ID: ADCDisabledMail, version: 6. Code : 0x80070057,Description : The parameter is incorrect."
The LegacyExchangeDN (LEDN) attribute is not set by the Exchange RUS (Recipient Update Service).
NOTE: This article applies to Exchange 2000/2003 environments only.
Please push the RUS to update the LEDN attribute for the user.
Please also see the following Quest article SOL30592:
"LegacyExchangeDN (LEDN) attribute is missing on stub objects"