The SD-WAN implicit rule is a default rule that applies to all traffic that does not match any explicit SD-WAN rule. The SD-WAN implicit rule uses the best quality strategy, which selects the SD-WAN member with the best measured quality based on the performance SLA metrics. This means that the traffic load balance for the overlay interface will depend on the quality of each overlay member, which may vary over time. However, if the requirement is to minimize the overhead on the device for WAN traffic and avoid load balancing for the overlay interface when all members are available, one option is to configure the cost in each overlay member to 10. The cost is a parameter that can be used to influence the selection of an SD-WAN member by adding a penalty value to its quality score. By configuring the same cost value for all overlay members, the quality score of each member will be reduced by the same amount, which will make them less preferable than the underlay members. This way, the SD-WAN implicit rule will select the underlay members first, unless they are unavailable or out of SLA, and only use the overlay members as a backup option. Reference: https://docs.fortinet.com/document/fortigate/7.0.0/sd-wan/19662/sd-wan-rules

A is correct because the scan order must be changed to antispam-sandbox-content in order for FortiMail to scan the email for spam and viruses before forwarding it to the third-party service.
B is correct because the Catch-All profile must be applied to the CFInbound profile in order for FortiMail to forward clean emails to the third-party service.
E is correct because an IP policy must be created with a Source value of 100.64.0.72/32 in order to allow emails from the third-party service to be delivered to FortiMail.
The other options are not necessary to meet the requirements. Option C is not necessary because the access receive rule will already allow emails from the third-party service to be received by FortiMail. Option D is not necessary because the Catch-All profile already allows emails to be delivered to any destination.
Here are some additional details about integrating a third-party service into the FortiMail email processing path:
The third-party service must be able to receive emails from FortiMail and send them back to FortiMail.
The third-party service must be able to communicate with FortiMail using the SMTP protocol.
The third-party service must be able to authenticate with FortiMail using the SMTP AUTH protocol.
Once the third-party service is integrated into the FortiMail email processing path, all inbound emails will be processed by FortiMail as usual. If the email is clean, FortiMail will forward it to the third-party service. The third-party service will then send the email back to FortiMail for final delivery. FortiMail will not scan the email again.

B is correct because a client can be eligible for multiple enabled configurations on the EMS server, and one will be chosen based on first priority. This is explained in the FortiClient EMS Administration Guide under Deployment & Installers > Manage Deployment > Managing deployment configuration priority levels. C is correct because you can only deploy initial installations to Windows clients using FortiClient EMS. This is also explained in the FortiClient EMS Administration Guide under Deployment & Installers > Deploying FortiClient software to endpoints. Reference: https://docs.fortinet.com/document/forticlient/7.0.7/ems-administration-guide/278884/deployment-installers https://docs.fortinet.com/document/forticlient/7.0.7/ems-administration-guide/374506/deploying-forticlient-software-to-endpoints