Interaction Attributes Technical Reference
Interaction Client sets this attribute to indicate whether a call should be disconnected or sent to Voice Mail as part of a consult transfer. The related handlers need to know that a particular call is the consult-transfer call of a transfer operation so that the call can be disconnected instead of routed to Voice Mail. When this attribute is set to zero, the call is not considered to be part of a consult transfer and will be disconnected. If set to "1" when a call is transferred to a user queue, the call goes directly to voicemail without attempting to alert the user.
The Eic_SendToVoiceMail attribute has no connection to the TransferToVoicemail value of Eic_Capabilities.