When moving a SmarterMail installation from one server to another it is best to minimize the downtime. When a SmarterMail install has many Gigabytes or more of data it can take a long time to copy from one server to another, causing an increase in downtime.
To help minimize the downtime and speed up the migration process, Robocopy can be used to copy the data over a few days before the move, then use it again to ONLY copy the changed data. Doing the bulk of the migration ahead of time, then simply copying over just the changed data means that final step in the migration process is much smaller and will minimize the downtime.
IMPORTANT NOTES: SmarterMail data should be migrated to a new server that's running the same build number. Do not follow these steps to migrate a SmarterMail 16.x or prior installation to a new server running the current 100.0.xxxx build. If you wish to upgrade along with your migration, you must migrate to the server then perform the upgrade, or perform the upgrade on the old server then migrate.
To migrate SmarterMail to a different server using Robocopy, follow the command below:
C:\>Robocopy [source] [destination] /MIR /ZB /R:1 /W:3
This will mirror the data, will retry once, then wait 3 seconds before attempting a retry if there is any connection issue.
Here's an example:
C:\>Robocopy C:\SmarterMail\Domains \\SmarterMail_New\SmarterMail\Domains /MIR /ZB /R:1 /W:3
NOTE: When using the /MIR command this will overwrite any data in the destination folder that does not match the source folder.