Restrict email relay for one mail box

Question

Hi,

There is one mail box which is configured in application server to relay the email outside of organization.

Is there any way to restrict that mail box to relay mail from that particular server only in order to avoid miss use.

Exchange 2019 on premise evironment.

Answer 1

Hi @Mohammed Nadeem ,

Is there any way to restrict that mail box to relay mail from that particular server only in order to avoid miss use.

I am afraid no, it's not possible in the Exchange on-premises environment.

Assuming it's a standard user mailbox with credentials, it's crucial to keep the password secure and avoid sharing it with unauthorized individuals.

In addition, you can consider enabling and configuring the mailbox audit log for this mailbox. It can audit the ClientIpAddress and ClientMachineName, so you can search the audit logs regularly to see if there are any suspicious activities.

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Answer 2

Hello there,

Restricting email relay for a specific mailbox typically involves configuring mail server settings to prevent unauthorized users from sending emails through that mailbox. The process may vary depending on the mail server software you are using (e.g., Microsoft Exchange, Postfix, Sendmail, etc.). Below, I'll provide a general outline of the steps you can follow to achieve this on a typical mail server:

Identify the mail server software: Determine which mail server software you are using, as the configuration steps can differ for each server.

Access mail server configuration: Log in to the mail server's administration panel or access its configuration files. This may require administrative privileges.

Locate the relay settings: Find the section of the configuration that handles email relay settings. Depending on your mail server, this might be named something like "SMTP relay," "Relay permissions," or "Outbound relay."

Allow internal relay only: Modify the relay settings to allow relay only for internal emails originating from your organization's domain. This ensures that only authenticated users within your organization can use the mailbox to send emails.

Authenticate users for relay: If you need to allow certain external users or applications to relay through this mailbox, you can enable authentication and provide secure credentials (username/password) for those authorized users or devices.

Deny relay for the specific mailbox: Add a specific rule to deny email relay for the mailbox in question. This will prevent unauthorized users from using this mailbox to send emails, even if they have authentication credentials for other mailboxes.

Save and apply changes: After making the necessary modifications, save the configuration changes and apply them to your mail server.

Test the configuration: Perform testing to ensure that the relay restrictions are functioning as expected. Attempt to send emails through the restricted mailbox from different scenarios to verify that unauthorized access is blocked while authorized users can still use it.

I used AI provided by ChatGPT to formulate part of this response. I have verified that the information is accurate before sharing it with you.

Hope this resolves your Query !!

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