There are changes and enhancements to return receipt behavior on both outgoing and incoming mail messages.
For Notes client users, the administrator can configure the behavior through policies:
For Inotes clients the Return Receipt behavior is set via notes.ini settings:
iNotes_WA_SendReturnReceipt=2 display prompt giving user the choice whether to acknowledge the return receipt
iNotes_WA_SendReturnReceipt=1 always send return receipt – default behavior
iNotes_WA_SendReturnReceipt=0 do not send return receipt