Creating a transport rule to bypass safe attachments
You can create a transport rule, also known as a mail flow rule, in the Exchange admin center to bypass safe attachments scanning.
To understand how you create a transport rule that bypasses scanning, review the following steps:
Open a browser and navigate to the Office 365 portal.
On the Office 365 Home page, click the Admin tile or select it from the App launcher to open the Office 365 Admin center.
In the left navigation pane, click Admin centers > Exchange.
In the Exchange admin center (EAC), select mail flow in the left navigation pane.
Select rules in the top navigation list.
Click the New (+) icon, and then click Create a new rule.
Specify a name for your new rule.
In the Apply this rule if… list, select an option, such as The sender is located… > Inside the organization, and then click OK.
Note: You can choose from several options, such as The sender is a member of… or The sender address includes…. You can also set other criteria, including specifying senders, recipients, distribution group members and attachment types.
Click More options….
In the Do the following… list, select Modify the message properties… > set a message header.
In the Set the message header phrase, click the first instance of Enter text…, type X-MS-Exchange-Organization-SkipSafeAttachmentProcessing as the header name, and then click OK.
In the Set the message header phrase, select the remaining Enter text…, and then type something, such as a space, and then click OK. (This value is not actually used by the system even though something is required for the rule to work.)
- To save your settings, click Save.