I'm in the process of slowly migrating users from Lotus Notes. All inbound mail is directed to the Notes server, and mail for users on the new server is being relayed to the IredMail server (forwarded via SMTP to mydomain.local an alias domain on the IRedMail server). All users have accounts on both servers, but only one is used, and they are in the same domain.

I've been struggling with getting mail from the IRedMail server to users on the Notes server (other outbound mail works fine).

Noteserver.mydomain.com         IP 192.168.1.2
Iredmailserver.mydomain.com   IP 192.168.1.3

When a user on the IRedMail server sends mail to a user on the Notes server I want to relay the mail back to the notes server.

For Example,

User1@mydomain.com on the IRedMail sends mail to User2@mydomain.com who is on the Notes Server.

What setting would I enter in User2@mydomain.com's Relay/Transport settings in the admin panel to get mail back to the Notes server?

Thanks,
Mark