Mail migration fails with the following error message:
CONFIG_TEXT: Failed to copy mail content of subscription. Most probably that happens because of a network-related issue. Check network connections between source and target servers, then run migration for that subscription once more.
Migration tools tried to perform operation in 3 attempts: Command execution failed on the local server with non-zero exit code.
command: "C:\Program Files (x86)\Plesk\admin\plib\modules\panel-migrator\backend\lib\python\parallels\core\extras\mail-migrator\windows\MailMigrator.exe" list-message-ids --account-description-file="C:\Program Files (x86)\Plesk\var\modules\panel-migrator\sessions\20191015091512\target-server\mail\example.com\jonn.doe\mailbox-description" --output-file="C:\Program Files (x86)\Plesk\var\modules\panel-migrator\sessions\20191015091512\target-server\mail\example.com\jonn.doe\exclude-message-ids"
exit code: 2
stderr: Error: Object reference not set to an instance of an object.
SmarterMail 100 is installed on the destination server.
Migration to and from SmarterMail version 100.x is not supported. It is a known Plesk Migrator bug with the ID PMT-4672 and will be fixed in the next Plesk Migrator update.
Currently, no workaround is available.