Fix email delivery issues for error code 5.7.133 in Exchange Online

It's frustrating when you get an error after sending an email message. This topic describes what you can do if you see error code 550 5.7.133 in a non-delivery report (also known as an NDR, bounce message, delivery status notification, or DSN). You'll see this automated notification when the recipient is a group that's configured to reject messages from external senders, that is, senders from outside the organization.

Icon Message Icon Message
Email user icon. I got this bounce message. How do I fix this issue? Email admin icon I'm the group owner or email admin. How do I fix this issue?

I got this bounce message. How do I fix this issue?

Only the group owner or an email admin in the recipient's organization can fix this issue. Contact the group owner or email admin and refer them to this information so they can try to resolve the issue for you.

I'm the group owner or email admin. How do I fix this issue?

The two methods that will allow an external sender to send messages to the distribution group in your organization are described in the following sections.

To open the Exchange admin center (EAC), see Exchange admin center in Exchange Online.

Method 1: Allow all internal and external senders to send messages to this group

New Exchange admin center (EAC)

  1. Go to Recipients > Groups.

  2. Select a group from the list and click it. The group properties screen appears.

    The screen displaying the properties of the chosen group.

  3. Click the Settings tab.

    The screen on which group details are displayed.

  4. Under Delivery management, click Edit delivery management. The Delivery management screen appears.

  5. Under Sender options, choose Allow messages from people inside and outside my organization.

    The screen on which all the senders are added to the senders group.

  6. Click Save changes.

Classic EAC

  1. In the EAC, go to Recipients > Groups > select the group from the list, and then click Edit Edit icon..

The screen that displays the groups option.

Finding groups in the Exchange admin center.

  1. In the group properties dialog box that opens, go to Delivery management > select Senders inside and outside of my organization.

The Delivery Management screen to configure all senders to send mails.

Use the Exchange admin center to solve DSN 5.7.133 and allow senders.

  1. Click Save.

Method 2: Use the group's allowed senders list

Instead of allowing all external senders to send messages to this group, you can use the group's allowed senders list to selectively allow messages from all internal senders and the specified external senders.

Notes:

  • To add an external sender to a group's allowed senders list, you must first create a mail contact or a mail user to represent the external sender in your organization.

  • To add everyone in your organization to a group's allowed sender's list, you can create a distribution group or a dynamic distribution group that contains everyone in your organization. After you create this group, you can add it to the group's allowed senders list.

  • The group's allowed senders list is different from the organization's allowed senders list for anti-spam that you manage in the EAC at Protection > Spam filter.

To configure the group's allowed senders list, perform the following steps:

New EAC

  1. Go to Recipients > Groups.

  2. Select a group from the list and click it. The group properties screen appears.

    The screen displaying the properties of the chosen group.

  3. Click the Settings tab.

  4. Under Delivery management, click Edit delivery management. The Delivery management screen appears.

  5. Under Sender options, choose Allow messages from people inside and outside my organization.

  6. Under Specified senders, click inside the text box. The list of senders (internal and external) is displayed.

    The screen that lists the internal and external senders who can be added to the senders list.

  7. Choose the senders you want to add to the senders list, and click Save changes.

    The screen on which a chosen sender is added to the senders group.

Classic EAC

  1. Go to Recipients > Groups > select the group from the list, and then click Edit Edit icon..

  2. In the group properties dialog box that opens, go to Delivery management and configure the following settings:

    • Select Senders inside and outside of my organization.

    • Click Add Add icon.. In the Select Allowed Senders dialog box, select and add the external senders and the "all internal users" group. When you're finished, click OK.

    The screen on which the option to add a sender is displayed.

The screen on which you can add a sender who is to be added into the.

Add allowed external sender to a distribution group to help solve NDR 5.7.133.

  1. Click Save.

Still need help with error code 550 5.7.133?

Get help from the community forums.

Admins: Sign in and create a service request.

Admins: Call Support.

See also

Email non-delivery reports in Exchange Online

Create and manage distribution groups in Exchange Online.