This command will create a file at /decide/zimbra/tmp/modules/travel/accounts-generate-data.tgz made up of all the information linked to the Generate module for comma-divided accounts about the server. The sole Option is to migrate all customers to O365 and add MX history. As temp Resolution is as you claimed onmicrosoft.com , I utilised https://acelle-mail30369.wikiinside.com/730690/considerations_to_know_about_zimbra_migration_service