Be sure to set the Default Mark Options for your organization before using this guide. The rules created in this guide will override the default policy based on the criteria you choose, but in many cases the default policy may be sufficient for your needs.
Prerequisites
EchoMark should already be set up and connected to your Exchange instance. Your initial mail rule will route mail through EchoMark You can layer in more mail flow rules to set marking options based on message sender, receiver, or other message content. You'll need to be an Exchange Administrator in order to access and update mail flow rules.
Step 1: Navigate to the Exchange Admin Center
Access Exchange's mail flow rules at the following link: https://admin.exchange.microsoft.com/#/transportrules
Step 2: Create a new rule
Select the "Add a rule" menu item, located the "Rules" heading of the page linked above, then choose "Modify messages" from the dropdown menu that appears.
Step 3: Set rule conditions
Set the rule conditions based on your organization's needs. In the example shown below, the rule is applied when the sender is part of the Accounting group, but policy could just as easily be applied using a security label or keyword in the subject.
Under "do the following," you'll want to choose "Modify the message properties," and "set a message header." Type in "x-echomark-options" for the message header, and then add a policy ID that matches one of your organizations Marking policies for the header value.
Step 4: Save the rule
You can optionally set an enforcement policy for the rule, or simply leave the default settings, then save the rule.
Step 5: Order the rule appropriately
Only one X-EchoMark-Options header can only be applied per message, which means that a message that meets criteria for multiple mail flow rules that set the X-EchoMark-Options header will get the options that are applied via the last rule before it is routed through EchoMark. So you'll want to order this rule in the mail flow rules list to apply the header at the appropriate part of the flow. Usually, the top of the list is fine.
Step 6: Wait
It usually takes at least a half hour for the mail flow rule to activate in Exchange. Once it does, your mark options should start to take effect.