Currently when the sender of Org A sends the mail to recipient of Org B over internet address (consider both are not visible to each other over Notes addresses and prevented from looking up each other), then the "From" address of the sender is shown as Notes address to the recipient. So recipient has no way to reply to this mail unless the Notes address of original sender is replaced by internet address manually. Although manually replacing the address would allow the mail to be sent successfully but this is not very user friendly and the internet address of sender should come in "To" field.
So there is a feature request to give control to an Administrator to decide whether the "From" field of the mail should contain "Notes address" or "Internet address" and if this should be applied to all mails or only to mails sent to different Org. This will allow an Administrator to decide which address should be kept in "From" field.
This Enhancement Request is submitted for Domino Server 12.0.2 and above versions.
The from field is already configurable, as documented at https://help.hcltechsw.com/domino/14.0.0/admin/conf_howdominoformatsthesendersinternetaddressinoutbo_r.html
So all the admin has to do is configure the address lookup as explained in the documentaiton.