How to create a no-reply mailbox in Microsoft 365

UPDATE This post was updated on December 10, 2021.

No-reply email addresses are useful in many scenarios, like sending notifications from transaction systems, shipping progress information, etc. In the case of such messages, you do not expect any user feedback and most of them are generated and sent automatically.

Even though you cannot stop users from sending emails to a no-reply address, you can create a mailbox which will block all incoming traffic, meaning you will not have to monitor it.

How to create a no-reply mailbox

Before you start using a no-reply email address, always consider its applications and consequences of using it. Having user experience in mind, you can consider adding an automatic response to a no-reply mailbox. It’s a good practice to inform your recipients that they sent their message to the wrong address and tell them how to contact you if not by replying to the email they’ve just received.

If your use case requires no responses at all, instead of going through all the trouble of setting a no-reply mailbox, you can use a non-existent email address as a reply-to address. Just remember, no-reply mailboxes can cause you to lose valuable leads and leave your customers completely unsupported. That’s why, at least in some cases, it may be better to use a mailbox that someone in your organization actually opens and reads through. At least from time to time.

Creating a no-reply address using a shared mailbox

You can create a no-reply address by using a shared mailbox in Microsoft 365, since this kind of mailbox does not need a license. Given its use, you probably do not want to assign a license to a no-reply mailbox. To create a shared mailbox, open the Exchange admin center. Go to Recipients > Mailboxes and click the Add a shared mailbox button. Optionally, you can use filters to display shared mailboxes already created in your organization.

Create a shared mailbox

Assign an email address and display name according to the mailbox’s function. Although using an address like [email protected] is incredibly popular, it may be bad for the user experience. An address like that can suggest that you do not want to hear from your recipients. So, it might be better to think of something more friendly like [email protected] or strictly functional and appropriate to what the address will be used for e.g. [email protected]. In this example, I’ll go with the newsletter theme, so I’ll also use the Company Newsletter display name. You can also choose the appropriate domain (if you have more than one) and alias. If I leave the Alias field empty, its value will be identical to whatever I wrote in the email address field. Click Create to apply changes.

Add a shared mailbox - settings

With this done, you can immediately use the Add users to this mailbox option. It will let you use  the search field or the user list in the window that opens to select users who will become members of this mailbox (by default this user will have Full Access and Send As permissions to this mailbox). This is useful for sending emails using the no-reply address or if you would like to set up an automatic reply using Outlook.

Add users to shared mailbox

When you have created your shared mailbox, I recommend taking one of the two approaches. You can choose to block all emails or create a no-reply mailbox that will delete all the received messages and send an autoreply if someone writes to it.

Blocking all incoming emails

In the first scenario, I will use the shared mailbox to create a no-reply address that does not require monitoring. You can either set it up so that  emails are purged without letting anyone know or send out an NDR.

To create a rule that blocks incoming emails, open the Exchange admin center. Go to mail flow > rules. Click Add and select Create a new rule from the drop-down list.

New mail flow rule

Name the new rule e.g. No-reply blocking. In the Apply this rule if list select The recipient is.

Mail flow rule configuration

In the window that opens, select the previously created shared mailbox from the list (in my case this will be Company Newsletter[email protected]). Click add and confirm by clicking OK.

Select mailflow rule mailbox

If you want to delete the incoming emails without a trace, in the Do the following list, select Delete this message without notifying anyone.

Select mailflow rule action

If you want to inform the sender that their email never reached you, use the Reject the message with the explanation option. You will be able to add a short note, for example: This is a no-reply mailbox. Go to www.example.com/contact to see how to reach us. Finally, click Save to create the mail flow rule.

Noreply mailboxes - Set up NDR

When this is done, any email sent to [email protected] will be deleted before it reaches the inbox. As a result, you do not have to assign an employee to monitor this address. If someone decides to send an email to this address anyway, they will never receive a reply from you (obviously), but they might receive a non-delivery report, depending on which option you chose.

Although you can add an explanation to the NDR, many users will not see it. Non-delivery reports aren’t built for end-user’s convenience – the message that you can customize is neither well visible nor appealing. If you would like to remedy this, you can take another approach.

Setting up a no-reply address with an automatic reply

In the second scenario, instead of deleting all incoming emails immediately as in the example above, I’ll configure a retention policy that will remove any emails from the inbox of your no-reply mailbox after a specified time period that can be as short as 1 day. If you prefer, you can set up a longer email retention period so you (or another employee) will have the opportunity to look through the incoming mail. Additionally, let’s set up an automatic reply that will notify any potential sender that this mailbox is not monitored regularly.

Begin by opening the Microsoft 365 compliance center. Go to Policies > Retention and click New retention policy.

New retention policy

In the Name page choose how to call your retention policy, e.g. No-reply mailboxes. Confirm by clicking Next. In the Locations page, select Exchange email. Then, click Edit in the Included column.

No reply mailboxes - policy edit

Use the search field or the mailbox list to find and select your no-reply mailbox. Confirm by clicking Done.

No reply mailboxes - choose mailbox

Click Next to go to Retention settings. Select Only delete items when they reach a certain age. In the Delete items older than drop-down list select Custom and use the fields provided to delete items older than 1 day. Then, in the Delete content based on drop-down menu select When items were created.

No reply mailboxes - policy action

When you click Next, you will go to the summary page. Click Submit to create the new policy. Note that it may take some time before it comes into force.

Configure an automatic reply

With the retention policy in place, I can now set up an automatic reply for the no-reply mailbox. There are a number of methods to do this, but in general the setup is identical to creating an out of office message. This article explains in detail how to set up automatic responses in Microsoft 365 via the admin center or PowerShell. Below, you can find a short instruction on how to do it using the Microsoft 365 admin center.

Open the Microsoft 365 admin center and go to Groups > Shared mailboxes. Then, select your no-reply mailbox by clicking on it. In the new pane that opens, click Edit in the Automatic replies section.

Open autoreply settings

In the Manage automatic replies pane select the Send automatic replies to senders inside this organization and Send automatic replies to senders outside this organization checkboxes. Also select the Send replies to all external senders radio button. Enter your automatic reply text in the fields provided and click Save to confirm.

no reply - autoreply create EAC

Once again, have the user experience in mind when creating an automatic response. In most cases, a short reply like This email address is not monitored. If you would like to contact us, please write to [email protected] should work.

However, you may also want to provide some additional information depending on the context of the message to which the user is trying to respond, e.g. if it was a newsletter, you may direct users to contact the sales department or visit the product page, etc.

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21 thoughts on “How to create a no-reply mailbox in Microsoft 365


  1. I have set up a non-reply email address with an auto-reply. However, my challenge is that the auto-reply only sends one time to the sender when the sender could/will forget not to send to this address again. How can I set up the auto-reply to send each time an email is sent regardless of whether the auto-reply was sent before to the sender? Thanks!

    • Sending each time is not a good idea – it creates a risk of auto-reply loop, so you need a way to limit those replies to e.g. 1 per day per email address. The only reliable solution would be a third-party solution, like CodeTwo Autoresponder for Microsoft 365. It’s an integral part of our email signature management solution. Apart from letting you send multiple autoreplies per email address, it lets you send fully branded automatic replies, manage out of office messages and set them up with smart scheduling.

  2. Lot’s of people don’t seam to know this but
    the Out-Of-Office reply of Exchange, replies only once per emailaddress.
    This untile you deactivate and reactivate it.
    So this way is not really gonna work.
    You could set a server rule in Outlook to reply to every mail, but this may cause ping-pong storms between 2 autoreply addresses.
    I don’t know of any other solution, maybe power automate?

    • There is a solution which allows you to send, for example, 1 automatic reply per day for a specific email address: CodeTwo Autoresponder for Microsoft 365. It’s an integral part of our email signature management solution, which lets you send fully branded automatic replies, manage out of office messages and set them up with smart scheduling.

  3. Hi,

    I have tried so many times but all my comments get deleted.

    I have followed the guide and all seems to be working except that the reply are not being sent out. I can see in my outlook that auto reply is set but still no reply are getting out.

    I have followed every steps and dont think have missed anything.

    Please help here.

    • Hi,
      You can check a few things:
      1. Make sure the autoreply is set up for the shared mailbox. If it is, see if it’s configured for both internal and external contacts.
      2. Run a message trace to see if the incoming messages actually reached the shared mailbox. If they were rejected or deleted before they reached the mailbox, no autoreply will ever be sent.
      Finally, you can use the Reject the message with the explanation option instead of using a standard autoreply.

  4. Great article! Love how you makes every step super clear.
    However I had some problems setting up the retention. My newsletter email address that I created in the first step didn’t show up when I wanted to include it in my retention.
    Do you know what I am doing wrong? Its’ so frustrating.

    • If it doesn’t appear in the search immediately, it might need some time to propagate. You can try relogging after a while and see if the mailbox appears then.

  5. Hi Adam,

    It doesn’t work, the I followed your instruction the retention policy has been applied, but the mailbox does not delete incomming mail after a day. Any ideas?

  6. Why not use “Reject the message with the explanation”? It seems like the long way around accepting the message, deleting the message, and then, adding a retention policy, then adding an auto-reply?

    • Sure, you can use the “Reject the message with the explanation” action and it’s probably the most common option. I honestly don’t know why I didn’t include it in the article.
      The only downside is that you are very limited when it comes to how an NDR looks like and a standard autoresponder is more human-friendly.

  7. Why do you accept the emails only to reject them? Isn’t it simpler to set the Reply-To address on outbound mail to a fake email account so that any replies sent to that address fail to send at the user end. Why clutter up your email system?

    • That’s not a bad idea. However, having a fake or outbound reply-to email address can be viewed as suspicious and doesn’t allow you to set up the reason in the NDR message the sender receives.

  8. Thank you for the suggestions! I think the first would work better (best to manage) but doesnt inform the sender that the email didnt reach the noreply mailbox. Also, you could choose to inform the recipient by applying a different rule, from the list, “reject with reason” (not sure if thats the right name, i have my exchange in portuguese), but it would pass some intel to the recipient, so i choose the second one. Thanks once again!

  9. Hi,
    We have been using a noreply email address for a while now and have been sending about 300-400 emails per day with orderconfirmations etc. with a timespan of 40 seconds between each email.

    But now we are getting error “550 5.1.8 Access denied”.
    And after removing the block the address is getting blocked again as soon as we start up again.

    Any suggestion on what we can do about this?

    • This knowledge base article shows how to solve the Access denied problem. The address might be blocked again because you normally need to wait for around 2 hours after unblocking an address before attempting to send emails again.

  10. Adam, thanks for the great write-up. How would you use it programmatically to send emails? It doesn’t have a password, so how would you authenticate and send emails on behalf?

  11. This is a great write-up! It would even better if you included instructions for checking the shared mailbox that’s been created. Nonetheless, this is great!

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