Foreign cc:Mail domain document - Mail Information tab
FieldEnter
cc:Mail MTA server The name of the Domino server running the cc:Mail MTA software, for example ccMTA/Acme.
Default cc:Mail post officeThe name of the cc:Mail post office to which the MTA server should route messages addressed to the cc:Mail domain specified on the Basics tab, for example, acmeccpo.

For example, Domino server would route mail addressed to Rafael Morena@CCMAIL to the cc:Mail MTA server specified in the previous field, which would then route mail to the default cc:Mail post office acmeccpo.