Domino/Exchange Single Internet Domain Configuration

We have Domino/Notes applications which generate emails. We do not have mail-in databases and we are not using Domino as our mail system. Years ago, Domino was our mail system and migrated to exchange. Some configuration of that migration is still in place.

Currently, a person document would have jdoe@abc.com in the internet address and jdoe@exch.abc.com in the forwarding address. After a recent IT change, the forwarding address had to be updated to (jdoe@new.mail.com). Notes Client user's local contacts have the old "jdoe@exch.abc.com" and causing undeliverable messages to be generated.

  1. How do I configure Domino in a single internet domain where Domino is NOT the mail system and potentially eliminate using forwarding address?
  2. Is there something I can do to update/remove information stored in users recent contacts?
  3. How can the environment be configured if I wanted to implement a mail-in database functionality?

We have Global Domain config doc, Foreign SMTP domain doc (which should not be working anymore).

Trying to untangle the mess and simplify my environment. Any help or keywords would be greatly appreciated.

Some KAs regarding recent contacts.

How to reset the Recent Contacts view's contents in the Notes Client
https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0033261

How to disable the Recent Contacts feature in Notes
https://support.hcltechsw.com/csm?id=kb_article&sysparm_article=KB0034278

Append jdoe@exch.abc.com as another row in the Fullname field of the person document and change the forwarding address to jdoe@new.mail.com.

Add exch.abc.com as alias to the global domain configuration document in your Domino directory.

This way, the router task of your Domino server accepts emails to *@exch.abc.com as it does for *@abc.com. When it receives an email to jdoe@exch.abc.com, the router looks up the person document, finds the one with jdoe@exch.abc.com in its fullname, recognises the forwarding address and forwards the email to your Exchange server using jdoe@new.mail.com.

I think, adding jdoe@exch.abc.com to the fullname field might even be unnecessary, if jdoe is the short name of the user, but I'm not completely shure. May depend on some other configuration setting (look up fullname only).