suffered long from that until my company switched to Exchange and Outlook.
We had once a pilot in our IT where we use a middle are called DME (or was that the company ?) to connect Notes to iPhone. But they didn't went beyond the pilot.
When your IT and policies allows you can just install some eMail forwarding in Notes (was not allowed in my company). There is also a connector; depends on which Domino-Server you are.
I'm happy to got rid of LN; never really liked it ...