The mails sent from iNotes do not have iNetSendTo field. The mails sent from Notes Client have this field. When any custom application or third party tool is reading this field and doing some action then it is unable to process the mails from iNotes due to lack of this field. So there is a feature request that, iNotes should also populate the field iNetSendTo, iNetCopyTo, iNetBlindCopyTo etc. just like how Notes Client populates these fields.
This Enhancement Request is submitted for Domino V11.