Setting an autoreply for a distribution group in Exchange

First, let’s get one thing out of the way – distribution groups cannot send automatic responses by themselves.

Using Reject the message with the explanation / enhanced status code transport rule actions to send auto-replies for a distribution group is not a good idea either. Firstly, because it defeats the whole purpose of maintaining a distribution group (the original message is blocked, thus not reaching the members of the group). Secondly, because the automatic messages sent by the actions are very very bare-bones (as you can see here).

The most common solution to these grievances is a shared mailbox with a have server reply using a specific message rule underneath it.

Note: There is another way, that does not involve creating a new shared mailbox. It requires using a third-party solution such as CodeTwo Exchange Rules Pro. I discuss it in this section of the article.

Set up an auto reply for a distribution group

Follow the steps below to set up the whole mechanism:

Save the distribution group’s most essential properties:
LegacyExchangeDN (attribute used in Outlook’s and OWA’s auto-complete cache to route messages). You can get it by running one of the below scripts (depending on the type of the group):

Get-DistributionGroup “<distribution group’s id>” | Select LegacyExchangeDN

Get-DynamicDistributionGroup “<dynamic distribution group’s id>” | Select LegacyExchangeDN

List of members – To export the list to a CSV file run:

Get-DistributionGroupMember “<distribution group’s id>” -ResultSize Unlimited | Select alias | Export-CSV -Path “<target CSV file path>”

To export members of a dynamic distribution group use the second script from the top provided in this article. As well as any other properties you may want to. For example, you can easily export your dynamic distribution group’s primary properties by running the following cmdlet:

Get-DynamicDistributionGroup “<dynamic distribution group’s id>” | select name,includedrecipients,recipientfilter | Export-Csv "<target CSV file path>"
Delete the distribution group.
Create a new shared mailbox using the deleted distribution group’s SMTP address and grant yourself full access permissions to the mailbox.
Update the shared mailbox’s LegacyExchangeDN with the saved distribution group’s LegacyExchangeDN (as I mentioned earlier, this is necessary because of Outlook and OWA routing). You can easily do this via ADUC, by editing the LegacyExchangeDN entry in Attribute Editor.
Create a clone of the old distribution group using a new SMTP address (unless you want to abandon distribution groups altogether in this case and use e.g. a transport rule or Outlook rule which sends copies of emails to ex-members of the group).
Create an Outlook profile for the shared mailbox. To do this go to Control Panel > Mail > Show Profiles…. Choose the Prompt for a profile to be used, click Add….
Provide a name for the new profile, click OK, and complete the account creation wizard (leaving the password boxes empty).
Run Outlook in the shared mailbox’s profile.

At this point you could set up a standard Automatic Reply for the mailbox. However, this would limit the number of automatic responses to only one per sender (see this Microsoft article for details). Also, when sending messages to the shared mailbox, users would keep seeing an “Automatic reply” MailTip suggesting that the shared mailbox “recipient” is absent. That’s why, you may want to set up the auto-response by using Outlook rules. To do so:
Go to File > Manage Rules & Alerts >New Rule…
In the Rules Wizard, select Apply rule on messages I receive and click Next.
Configure the rule’s conditions to suit your needs or leave the conditions empty to apply the rule to all messages received by the shared mailbox. Click Next.
In the actions’ configuration step, select the below and click Next.
1. Have server reply using a specific message and create the message template that will be used as the auto-reply (the template can include attachments).
  Note: Regardless of how you fill out the TO, CC and BCC fields, the whole template will be sent to the original sender.
2. An action that will send the message to the new distribution group (e.g. forward it to or redirect it to).
Configure exceptions or leave this step blank and click Next.
Complete the last step and click Finish.
Test the setup by sending an email to the shared mailbox’s address.

Autoreply for a distribution group using CodeTwo Exchange Rules Pro

To set up an auto-reply mechanism for a distribution group using CodeTwo Exchange Rules Pro, follow these steps:

Create a new rule in CodeTwo Exchange Rules Pro.
Configure at least one condition, so that the rule will catch emails sent to the distribution group. For example, Recipient > matches AD user > <your distribution group>.
Configure an Auto respond action.
Save changes.