Hi @Dias DT That is the expected actions you explained above. Should you issue the MX record to O365, this will help make sure email is sent to your Microsoft 365 or Office environment 365 mailboxes. Going the MX history may also let you switch off your old email process https://free-mail-zimbra-migratio79900.plpwiki.com/6072472/about_zimbra_migration_service