We are expecting to set up a lot of Email Forwarding requests that will be directed to an email connector email on fivetran.

To make things easier, we believe that you can configure your logging system to 

Include an Event LOG for each email receive with
the contents of the email received (subject and body) which will contain the VERIFICATION code needed for autoforwarding.

This process will definitely solve a lot of issue and will lower our support requests as we always need to create a ticket just to see the verification code from the autoforwarding.

This will also be helpful when troubleshooting and tracking emails received.