I have an ongoing FortiMail POC. Please see attached image for reference.
So far with the proposed topology all inbound emails are now passing and filtered by FortiMail and handover those cleaned emails to Zimbra.
Outbound email traffic is sent directly to the Internet due to Zimbra has its own DKIM configuration.
Since Zimbra Email Server is the one holding the DKIM configuration and I want all outbound emails would be subject to FortiMail inspection. Do I need to offload the DKIM configuration from Zimbra and configure DKIM inside FortiMail?
Is there any issue if DKIM is still on Zimbra and Outbound emails will be forwarded to FortiMail?
Appreciate any word of advice for this setup. thank you in advance.