I've been doing help desk for 10 years or so. You can't set an internal URL on the Autodiscover virtual directory. Select the name of the user (from whom you plan to give a sending permission) to open their properties pane. By default, this box is selected. Every shared mailbox has a corresponding user account. To open the EAC, see Exchange admin center in Exchange Server. You can forward the messages to any valid email address or distribution list. The message will appear to be sent by the group and will say that it was sent by the delegate on behalf of the group. None: This option specifies that the mailbox won't reject messages from any senders in the Exchange organization. In the new EAC, navigate to Recipients > Mailboxes. Exchange 20XX - All external email to have the same corperate font and font size? This enables them to be included in the global address list (GAL) and added to distribution lists. For other recipient types, use the corresponding Set- cmdlet with the same parameters. Step 1: Sign into Office 365 admin portal via https://portal.office.com Step 2: Click on Admin from the left pane and navigate to Groups > Active groups. The length of a custom MailTip can't exceed 175 displayed characters. Replace the example values with the server names, FQDNs, and IP addresses for your organization. To verify that you've successfully created a mail-enabled security group, do one of the following: In the new EAC, navigate to Recipients > Groups > Mail-enabled security. Spice (1) flag Report Was this post helpful? This might be a silly question, but I'm quite new to O365. Select the recipients you want, add them to the list, and then click OK. You can also search for a specific recipient by typing the recipient's name in the search box and then clicking Search . Select the desired OU, and then click OK. * Owners: By default, the person who creates a group is the owner. This option will not work with mail-enabled security groups because of security-related limitations. The mail-enabled security group must have at least one owner. You can just create a Transport rule for email send inside the organization to this mailbox and it will be blocked with a bounced email (See example below) http://www.msexchange.org/articles-tutorials/exchange-server-2007/management-administration/restrict. Having problems? If you want to change the primary email address, your mailbox must have more than one email alias. For example, if a user is assigned permissions to access a shared mailbox in a different geo location, mailbox actions performed by that user are not logged in the mailbox audit log of the shared mailbox. Check out the new Exchange admin center! Examples of recommended DNS records that you should create are described in the following table: To verify that you've successfully configured the internal URL on the Mailbox server virtual directories, do the following: Select a virtual directory and then click Edit . @Andy David - MVP Thanks for the quick response. For information about which parameters correspond to which distribution group properties, see the following articles: Here are some examples of using Exchange Online PowerShell to change security group properties. By default, only people inside your organization can send messages to this group. If you want to configure a unique Outlook on the web FQDN, do the following steps. Select the new certificate and then, in the certificate details pane, verify that the following are true: Assigned to services shows, at minimum, IIS and SMTP. You need permissions before you can do this procedure or procedures. Open the EAC and go to Servers > Servers, select your internet-facing Mailbox server that your clients will connect to, and then click Edit . For additional management tasks related to recipients, see the following topics: You need to be assigned permissions before you can perform this procedure or procedures. After you have created a shared mailbox, you'll want to configure some settings for the mailbox users, such as email forwarding and automatic replies. To increase the size limit to 100 GB, the shared mailbox must be assigned an Exchange Online Plan 2 license. Microsoft Exchange Online Management Sign in to follow 0 comments Report a concern For more information, see Default settings for Exchange virtual directories. For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard shortcuts in the Exchange admin center. How to allow external users to send emails to a list in Office 365? Based on your description, your shared mailbox cannot receive external emails. Specify the internal host name: Enter the internally accessible FQDN (for example, mail.contoso.com). For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard shortcuts in the Exchange admin center. Description: Use this box to describe the security group so people know what the purpose of the group is. Click the Delivery Restrictions button and uncheck the "Require that all senders are authenticated" checkbox: Click OK to commit the change. The alias can't exceed 64 characters and must be unique in the forest. However, I do not want this user to have access to the Global Address list, SharePoint, Skype, etc. Accept messages from: Use this section to specify who can send messages to this user. The display name is required and should be user-friendly so people recognize what it is. In Exchange Online PowerShell, use the Get-DistributionGroup cmdlet to verify the changes. Before clients can connect to your new server from the internet, you need to configure the external domains (or URLs) on the virtual directories in the Client Access (frontend) services on the Mailbox server and then in your public DNS records. Verify the external recipient receives the message. In this example, the final value would be https://owa.contoso.com/owa. Use the Get-DistributionGroup and Set-DistributionGroup cmdlets to view and change properties for security groups. In the example above where all security groups were hidden from the address book, run the following command to verify the new value. Before proceed, Connect Exchange Online Powershell module and use the following command to allow external sender. If you want to override your organization's group naming policy, see Override the distribution group naming policy. It includes external users only if you clear the Require that all senders are authenticated check box. Besides, is the shared mailbox in pure cloud environment? Totally agree with what michev has replied above. Block messages from: Use this section to block people from sending messages to this user. Internal emails to the shared mailbox are fine. Ask for help in the Exchange forums. You can't add images, only text. If you're configuring a mailbox to reject messages from senders that are members of a specific distribution group, use the RejectMessagesFromDLMembers parameter. Select the recipients you want, add them to the list, and then click OK. You can also search for a specific recipient by typing the recipient's name in the search box and then clicking Search . We recommend that you configure a user principal name (UPN) that matches the primary email address of each user. Hello! Users that have external email accounts have user domain accounts in Active Directory, but use email accounts that are external to the organization. Select the name of the user (whose mailbox you want to allow to be read) to open their properties pane. If you're configuring a mailbox to reject messages from individual senders, you have to use the RejectMessagesFrom parameter. Select the shared mailbox you want to edit, then select Members > Edit. This includes external users that are outside of your Exchange organization. Select Add permissions, then choose the name of the user or users that you want to allow to send email on behalf of this mailbox. Now we want all members in this group can send email with "send as" or "on behalf of" features in delegation setting, but seems these features are just be able to be applied to internal user as the external user is not shown in the drop-down Contact list. In this scenario, please try to create a new shared mailbox to check if the issue could be reproduced. Estimated time to complete this task: 50 minutes. Click Add to display a list of all recipients in your Exchange organization. In nslookup, type set type=mx and then look up the accepted domain you added in Step 1. Other options are Off and On. If it doesnt have an onmicrosoft email address, can you add a secondary email and send to that? On the group's properties page, click one of the following sections to view or change properties. Select Add permissions, then choose the name of the user or users that you want to allow to read email from this mailbox. A group in Outlook is like a shared mailbox. The message delivery restrictions covered in this topic apply to all recipient types. Under Set up the basics section, enter the details and click Next. Add senders who don't require message approval: To add/remove users that can bypass moderation for this group, search/add users from the drop-down list. If you want to apply advanced features such as Microsoft Defender for Office 365, eDiscovery (Premium), or retention policies, the shared mailbox must be licensed for those features. You do not need to assign a license to the shared mailbox in order to forward email that's sent to it. If you select the Owner approval is required check box, the group owner or owners receive an email requesting approval to join the group. Run the following command in the Exchange Management Shell. the security software will not allow mail through to the mailbox. I would setup a transport rule to block external emails sending to this shared mailbox. If you want to allow everyone to see the Sent email, in the admin center, edit the shared mailbox settings, and select Sent items > Edit. This example changes the primary SMTP address (also called the reply address) for the Seattle Administrators security group from admins@contoso.com to seattle.admins@contoso.com. You can add owners by clicking Add. Select the user you want, expand Mail Settings, and then select Edit next to Mailbox permissions. Select Add. If you're looking for information about creating and managing shared mailboxes, check out Create a shared mailbox. Select the shared mailbox you want to edit, then select Automatic replies > Edit. OAB (when accessed from the internet) and OAB (when accessed from the Intranet) should show mail.contoso.com. Can I assign a license to the mailbox itself, reset password and provide it to the external user, so he can log into the shared mailbox? In the list of groups, click the mail-enabled security group that you want to view or change. We have multiple people sharing a shared mailbox. Archived Forums 621-640 . The mail-enabled security group must have at least one member. Only sender: This is the default setting. On the mailbox properties page, click Mailbox Features. Reject messages from: Use this section to block people from sending messages to this user. Upgrade to Microsoft Edge to take advantage of the latest features, security updates, and technical support. Optionally, enter a duration, s note about the hold, and a URL with more information. By default, all new mail-enabled security groups require that all senders be authenticated. Read email in another user's mailbox In the admin center, go to the Users > Active users page. More info about Internet Explorer and Microsoft Edge, Keyboard shortcuts in the Exchange admin center. You might receive certificate warnings when you connect to the Exchange admin center (EAC) website until you configure a secure sockets layer (SSL) certificate on the Mailbox server. Notify all senders when their messages aren't approved: This is the default setting. Mail sent by anyone not in the list will be rejected. Only senders in your organization: When you select this option, only users or groups in your organization are notified when a message that they sent to the group isn't approved by a moderator. The Send As and Send on Behalf permissions do not work in Outlook Desktop client with the HiddenFromAddressListsEnabled parameter on the mailbox set to True, since they require the mailbox to be visible in Outlook via the Global Address List. To learn more, see Compare Groups. Of course I have no issues adding "someone@myorganization.com" to the mailbox, but the external user - "someone@externalorganization.com" simply can not be added to the shared mailbox. * Alias: This is the portion of the email address that appears to the left of the at (@) symbol. Send email from another person or group (article) Resource mailboxes: Select this check box if you want to include Exchange resource mailboxes. Shared mailboxes are used when multiple people need access to the same mailbox, such as a company information or support email address, reception desk, or other function that might be shared by multiple people. Under Edit email addresses page, change/edit the Primary email address, add/delete Aliases, and then click Save changes. Mailbox conversion: You can convert user mailboxes to shared mailboxes. More info about Internet Explorer and Microsoft Edge, Keyboard shortcuts for the Exchange admin center, Create a distribution group naming policy, Override the distribution group naming policy. Only allow messages from people inside my organization: Select this option to allow only senders in your organization to send messages to the group. Delivery has failed to these recipients or groups: finance@email address. Senders inside and outside of my organization: Select this option to allow anyone to send messages to the group. Reject messages from: Use this section to block people from sending messages to this user. If their UPN matches their email address, Outlook on the web (formerly known as Outlook on the web), ActiveSync, and Outlook will automatically match their email address to their UPN. If you've selected "Messages sent to this group have to be approved by a moderator" and you don't select a moderator, messages to the group will be sent to the group owners for approval. Click Add a group and follow the instructions in the details pane. To make the new address the primary SMTP address for the group, select the Make this the reply address check box. For some reason it isn't receiving external emails. For detailed syntax and parameter information related to placing delivery restrictions for different types of recipients, see the following topics: To verify that you've successfully placed message delivery restrictions for a user mailbox, do one the following: In the list of user mailboxes, click the mailbox that you want to verify the message delivery restrictions for, and then click Edit . You'll be shown how to do this later in this topic. This includes external users that are outside of your Exchange organization. Is this even possible? Senders in the following list: This option specifies that the mailbox will reject messages from a specified set of senders in your Exchange organization. The recommended DNS records that you should create to enable mail flow and external client connectivity are described in the following table: To verify that you've successfully configured the external URLs in the Client Access services virtual directories on the Mailbox server, do the following steps: In the EAC, go to Servers > Virtual directories. We have a hybrid system with no exchange server, only use o365 and AD schema extended attributes on onprem DC. Any suggestions? You can also allow people outside the organization to send messages to this group. Use this section to set options for moderating the group. Back at Servers > Virtual directories, select owa (Default Web Site) on the server that you want to configure, and then click Edit . Another option is to create a group for your shared mailbox. If you select this check box, messages from external users will be rejected. For example, you may have set the internal URLs to use internal.contoso.com. And more easily you could select the option: Required senders to be authenticated to reject outside senders. Manage another person's mail and calendar items (article) Choose the + (plus) button to add a new rule. For additional management tasks related to mail flow and clients and devices, see Mail flow and the transport pipeline and Clients and mobile. No senders: This option specifies that the mailbox won't reject messages from any senders in the Exchange organization. The following steps show you how to configure an SSL certificate from a third-party certificate authority (CA): Create an Exchange Server certificate request for a certification authority. Don't notify anyone when a message isn't approved: When you select this option, notifications aren't sent to message senders whose messages aren't approved by the group moderators. The ECP and OWA virtual directory internal URLs must be the same. This name appears in the shared address book, on the To: line when email is sent to this group, and in the Groups list in the Classic EAC. ? Click Add and then select one or more recipients. If you've selected Require moderator approval for messages sent to this group and you don't select a moderator, messages to the group are sent to the group owners for approval. To remove a person or a group, select the item, and then click Remove . Select Add permissions, then choose the name of the person who you want this user to be able to send as. You should always block sign-in for the shared mailbox account and keep it blocked. If more than one person is a member, and they send/receive emails they encrypted with their own keys, other members might be able to read the email and others might not, depending which public key the email was encrypted with. On the New security group page, complete the following fields: * Display name: Use this box to type the display name. (0 members and 1 guests). In Assign owners section, click + Assign owners, select the group owner from the list, and click Next. Senders inside and outside your organization will be notified when their messages aren't approved. Go to https://owa.contoso.com/owa and verify that there are no certificate warnings. In the admin center, go to the Users > Active users page. Group moderators can approve or reject incoming messages. Set the toggle to Off for any apps you don't want them to use. Select the recipients you want, add them to the list, and then click OK. You can also search for a specific recipient by typing the recipient's name in the search box and then clicking Search . Require that all senders are authenticated: This option prevents anonymous users from sending messages to the user. It can be any valid email address. Use this section to view or change the email addresses associated with the group. Also, the email address with the previous alias will be kept as a proxy address for the group. User permissions: You need to give users permissions (membership) to use the shared mailbox. One advantage of using Exchange Online PowerShell is that you can view multiple properties for multiple groups. For example, https://owa.contoso.com/owa. Without these additional steps, you won't be able to send mail to the internet and external clients (for example, Microsoft Outlook, and Exchange ActiveSync devices) won't be able to connect to your Exchange organization. You must make sure that the custom address you specify complies with the format requirements for that address type. This example configures the mailbox of Robin Wood to also reject messages sent by members of the group Legal Team 3. This means the mailbox will only accept messages sent by other users in your Exchange organization. If you configured your internal and external URLs to be the same, Outlook on the web (when accessed from the internet) and Outlook on the web (when accessed from the Intranet) should both show owa.contoso.com. If you add senders to this list, they are the only ones who can send mail to the group. The procedure below lets you choose whether you want users to use the same URL on your intranet and on the internet to access your Exchange server or whether they should use a different URL. I've created the Guest user in Azure AD, Assigned some licenses to the user but am still unable to add the user to the desired shared mailbox. For more information about internal and external URLs on virtual directories, see Default settings for Exchange virtual directories Virtual Directory Management. Verify that Outlook or the mobile device successfully creates the new profile. You need to be assigned permissions before you can perform this procedure or procedures. Am I missing something? As previously mentioned, this check box is displayed only when the Automatically update email addresses based on the email address policy applied to this recipient check box isn't selected. Encryption: You can't encrypt email sent from a shared mailbox. You shouldn't use the account to log in to the shared mailbox. HTML tags aren't counted in the limit. The shared mailbox uses in-place archiving. In the list of groups, click the security group that you want to view or change, and then click Edit . I've read that you can add the domain of the external organization to the tenant, but that does not seem like a good solution. Select the shared mailbox you want to edit, and then select Edit next to Name, Email, Email aliases. By default, the person who creates a group is the owner. When a user types the alias on the To: line of an email message, it resolves to the group's display name. Set the toggle to On, and enter one email address to forward the messages to. Name: This name appears in the address book, on the To line when email is sent to this group, and in the Groups list. Note: If you see the option is set as "Automatic system-controlled", most probably you have not configured the setting at all.