Auto Forward in Office 365

This article details the method for supporting auto forward configurations where the recipient of the auto forward is an external email address.  When such a configuration is in operation neither the sender email address or the recipient email address are authorised to send via the Mailsphere MTA's.  It is recognised that these configurations are sometimes necessary for forwarding email to 3rd party solutions, such as help desk systems, and as such we have provided the following guidelines to set up Office 365 transport rules to support this configuration.

Overview

To support auto forward of email to external email address the following configurations will be added to your Office365 account:

  1. A new AutoForward connector that will only be used in conjunction with transport rules
  2. A transport rule for any mailbox specific AutoForward rules
  3. A transport rule for any distribution groups with external members within them

Create a new connector

Go to the Admin screen of Office 365, select Exchange followed by Mail Flow.  Use the + button to add a new connector.

Define the mail flow scenario

Define the mail flow scenario

As this connector will be used to send email from Office365 to external domains select 'Office 365' in the From field and 'Partner organisation' in the To field. Click Next to continue

Name your new connector

Name your new connector

Provide an easy to understand name for your new connector, we recommend 'Auto Forward'.  Click Next to continue.

Usage terms of the new connector

Usage terms of the new connector

Unlike the Mailsphere primary connector this connector will only be used when a rule redirects to it.  Please select the top radio button "Only when I have a transport rule set up that redirects messages to this connector".  Click Next to continue.

Destination routing

Destination routing

So we can ensure that the email reaches its destination please ensure the top option is selected "Use the MX record associated with the partner's domain". Click Next to continue.

Encryption configuration

Encryption configuration

We recommend that TLS encryption should be left enabled. Only if you find errors delivering to email addresses as part of this rule should you consider disabling this protection.  Click Next to continue, review the configuration and click Next again to save the configuration.

Validate your configuration

You will now be asked to validate the connector.  To do this add an external email address (e.g. a hotmail.com, yahoo.com or gmail.com email address).  Once the validation for this external email address has succeeded you can click Save to confirm your configuration.

Supporting Auto Forward configurations

If an Auto Forward configuration is applied to a mailbox then the following configuration will need to be set up.

An Auto Forward can be configured in two different ways.

  1. By the Admin through the Admin Console: https://technet.microsoft.com/en-us/library/dd351134(v=exchg.160).aspx
  2. By the user through Outlook Web Client: https://support.office.com/en-gb/article/Forward-email-to-another-email-account-1ed4ee1e-74f8-4f53-a174-86b748ff6a0e

Add an Auto Forward Transport Rule

In the Mail Flow admin screen, select Rules and use the + button to 'Create a new rule'.

Defining the Auto Forward rule

Defining the Auto Forward rule

To configure the 'Auto Forward' type message rule you must first select the 'More options...'

Add the condition

Add the condition

Once you have selected 'More options...' you can select from the 'Apply this rule if...' list as shown above with 'The message properties' followed by 'include the message type'.

Select the Auto-Forward property

Select the Auto-Forward property

After selecting the include message type condition please select the Auto-Forward message type from the provided selection list.

Note that this also automatically generates a rule title for you.

Define the action

Define the action

Now select the action to take when this condition is met.  Select 'Redirect the message to...' and 'the following connector'.

Select your Auto Forward connector

Select your Auto Forward connector

Select the Auto Forward connector that you created in the previous steps and save the rule with the button at the end of the pop up window.

Add a Transport Rule for external members of distribution groups

Add a Transport Rule for external members of distribution groups

Select the + button under Rules to Create a new rule...

Add the condition

Add the condition

From the condition drop down list select 'The recipient is a member of...'

A list of internal email address and distribution groups will be displayed. Double click on the distribution groups that you wish to include in this transport rule.  You can add more later if you need to update the rule.

Add a second condition

Add a second condition

To add a second condition to this rule select the 'More options...'

An 'add condition' button will appear, click on this.

Add a condition for an external recipient

Add a condition for an external recipient

From the drop down list select 'The recipient...' followed by 'is external/internal'.

 

Select the recipient is outside the organisation

Select the recipient is outside the organisation

From the drop down list select 'Outside the organization' followed by OK.

Define the action

Define the action

Now select the action to take when this condition is met.  Select 'Redirect the message to...' and 'the following connector'.

Select your Auto Forward connector

Select your Auto Forward connector

Select the Auto Forward connector that you created in the previous steps and save the rule with the button at the end of the pop up window.