We currently use Notes for email but our parent organisation who acquired us 3 years ago use Exchange. We have some staff that have email accounts in both systems and need to be able to view both inboxes in a single Outlook instance to avoid clumsy switching between profiles. Everything works fine except if you send a new email from the Notes account to the Exchange account Outlook converts the email address to the Exchange canonical form that Notes doesn't recognise so the email bounces back. If there is an entry for the Exchange contact in the Outlook contacts or if this is a reply to an email it works correctly
If you set up a Gmail account in the same profile this works correctly in all cases.
My request is that it should be possible to have both a Notes and Exchange account within a single Outlook profile. This was all discussed in ticket CS0077029