Mailbox: Enable External Forwarding in Microsoft 365

You may need to take an additional step after creating a forwarding rule to allow forwarding to your Planability email.

When configuring email forwarding from Microsoft 365 to Planability for Mailbox import, an extra step may be required to finalise the setup. By default, Microsoft 365 accounts block automatic email forwarding as a measure of outbound spam protection.

If you need to make adjustments to the setting, a specific bounce message will appear in your Microsoft 365 inbox after trying to set up forwarding to Planability. The bounce message will contain the following line:

550 5.7.520 Access denied, Your organization does not allow external forwarding. Please contact your administrator for further assistance. AS(7550)

This bounce does not mean that Planability rejected the message (despite what it says). Microsoft 365 did not attempt to deliver it to Planability because your Microsoft 365 account is set to prevent automatic external forwarding.

Your Microsoft 365 administrator will need to allow automatic external forwarding for any 365 based email addresses you want to forward to Planability. 

We’ve created this guide to help your administrators find and change the outbound spam protection policy that is blocking your forward.

For Microsoft 365 Administrators

Below we have set out a step-by-step guide for changing the specific portion of the automatic forwarding settings needed to work with Planability.   

You can also refer to this Microsoft article: Configuring external email forwarding in Microsoft 365 which documents the security features they've put in place. 

Choose The Option That Best Fits Your Organisation

• Enable Automatic External Forwarding for All Mailboxes
• Enable Automatic External Forwarding for Individual Mailboxes

Enable Automatic External Forwarding for All Mailboxes

• Log in to Microsoft 365 Defender as a Microsoft 365 administrator and choose Email & collaboration > Policies & rules > Threat policies > Anti-spam policies or head directly to the Anti-spam settings page here: https://security.microsoft.com/antispam 
  If these options are not available to you, the Microsoft 365 user account that you have used to log in does not have sufficient permissions to make these changes. Make sure you are logging in as an administrator for your account. Note that the policies you see in your own admin may differ from the default policies shown here:

• Click on Anti-spam outbound policy (Default) and scroll down to click the Edit protection settings link at the bottom of the sidebar.

• Find the section called Forwarding Rules, and the dropdown list called Automatic Forwarding Rules. Pull that list down and choose On - Forwarding is enabled. Click Save at the bottom. 

Enable Automatic External Forwarding for Individual Mailboxes

• Log in to Microsoft 365 Defender as a Microsoft 365 administrator and choose Email & collaboration > Policies & rules > Threat policies > Anti-spam policies or head directly to the Anti-spam settings page here: https://security.microsoft.com/antispam
  If these options are not available to you, the Microsoft 365 user account that you have used to log in does not have sufficient permissions to make these changes. Make sure you are logging in as an administrator for your account. Note that the policies you see in your own admin may differ from the default policies shown here:

• Click + Create policy and choose Outbound.

• Give your new outbound spam filter policy a Name and Description.
• Click Next and search to find the user account you want to allow to forward, i.e. the email account that you are forwarding to Planability, which will display under the Users field after you select it. 
• Click Next again, scroll down to the Forwarding rules section, and click the dropdown under Automatic forwarding rules. Choose On - Forwarding is enabled, then click Next.  
• Review the settings on the last screen and click Create to create your new outbound policy for the specified user(s).