Zimbra with Fortimail

[rengoku]

I'm with a mail migration project, I have the scenario where I have to live with the Fortimail console, with the same domain, eg: "mail.algo.com" (Zimbra) and "mail.algo.com" (Fortimail). How can I make both systems receive the emails while I finish migrating to Zimbra.

Because when I try to send emails from fortimail to zimbra they don't arrive, but from zimbra to fortimal yes, this I assume is a relay issue, but I can't find the fault.

Thanks.