How to Restrict Email in Office 365

This is a popular request from our academic customers – How can we restrict student email accounts so they cannot send or receive outside of the organization? Here are the steps we use for Office 365:

How to Restrict Email Delivery in Office365

Note: In this example, we will restrict email for a group so they can only send and receive messages within the organization

1. Sign in o office 365 using an Administrator account.
2. On the left hand side, select Admin -> Exchange
3. On the left hand side, select Mail Flow
4. Restrict inbound
   1. Click on the + sign and select Create a New Rule
   2. Enter a name like “Do not allow inbound”
   3. Under Apply this rule if, select “If the sender is located” select “Outside this organization”
   4. Under Do the following, select “Reject the message with Explanation” and enter a message such as “External messages not allowed”
   5. Click on More Options at the bottom of the screen
   6. Scroll up to Apply this rule if, click Add Condition
   7. Select “The recipient is a member of” and select the group you want to restrict
   8. Click Save
5. Restrict Outbound
6. 1. Click on the + sign and select Create a New Rule
   2. Enter a name like “Do not allow outbound”
   3. Under Apply this rule if, select “If the sender is located” select “inside this organization”
   4. Under Do the following, select “Reject the message with Explanation” and enter a message such as “External messages not allowed”
   5. Click on More Options at the bottom of the screen
   6. Scroll up to Apply this rule if, click Add Condition
   7. select “The sender is a member of” and select the group you want to restrict
   8. Click Save
7. Test by:
8. Sending a message from an internal mailbox to another internal mailbox (this should work)
9. Sending a message from an internal mailbox to an external mailbox (this should NOT work)
10. Sending a message from an External mailbox to an internal mailbox (this should NOT work)