Hello @Dias DT That is the predicted behavior you described over. Should you point the MX record to O365, this can help make sure email is sent to your Microsoft 365 or Office environment 365 mailboxes. Going the MX document will even let you turn off your outdated email technique https://titusivgte.wikiconversation.com/6531519/the_ultimate_guide_to_zimbra_migration_service