After you have updated the primary domain, you can update any secondary domains in your system. To do so, follow the same process you used to update the primary domain, its post offices, and users.
To streamline the update process on NetWare and Windows, you can run the Agent Installation program (agents\install.exe) with the /copyonly startup switch, which copies the updated agent software files but does not perform any other agent configuration. On Linux, the Installation program offers separate file copy and configuration options to streamline the update process.
IMPORTANT: The MTA for the domain that the secondary domain links to should be updated and running before you update the secondary domain.