Share
Explore
Step By Step Setting Up Email Relay from multiple email

Enable-the-SMTP-relay-server-to-send-E-mail-message-on-behalf-of-other-mail-recipients.jpg

After creating the required setting for the IIS SMTP relay, we will need to solve the additional issue that can describe as Enable the IIS SMTP relay to send mail on behalf another Email address.

For the demonstration purpose, let’s use the following scenario:
We want to enable two internal Hosts, to send email using the IIS SMTP server.

One Host is a Helpdesk application that uses the Email address:HelpDesk@o365info.com, and the other host is a Fax machine that uses the use the email address: FaxService@o365info.com

In case that this Hosts will try to relay mail to the IIS SMTP server, that mail message will be rejected by the Exchange Online server because: by default, a recipient (in our example: John@o365info.com) cannot send email “on behalf” other recipient’s (in our example: FaxService@o365info.com and HelpDesk@o365info.com).

The good news is that we don’t need to create a user account and Mailbox that will “represent” these Hosts, who will relay mail to the IIS SMTP Server.

1. Using distribution group and assign “Send as permissions.”
This solution based on creating a distribution group for each of the Hosts who needs to relay E-mail to the IIS SMTP server. The distribution group configured as a security group (a Security/Distribution group).

The next step is: assigning “Send as permission” for the recipient whom the IIS SMTP Server use for authentication (in our example:John@o365info.com).

The Send As permission could be assigned by using the Web interface or by using a PowerShell command.

Assign “Send As” Permissions for a Mailbox/Distribution group

Assign “Send as permission” using the Office 365 Web management interface
Log in to Office 365 portal, in the Admin menu choose the option: Exchange
In the Exchange admin center choose the recipient menu –> groups
Click on the “Add” option and choose the Security group option.
Using distribution group and assign “Send as permissions” -01
In our example, we will name the new security-distribution group as FaxService
Double click on the name of the new security-distribution (FaxService) and choose the menu – group delegation.
Click on the add option and, add the recipient name that we use for the IIS SMTP credentials
(in our example: John).
Using distribution group and assign “Send as permissions” -02
We will need to repeat this procedure, for each of the LAN Hosts that will need to relay email using the IIS SMTP Server.

Assign “Send as permission” using PowerShell command

PowerShell command syntax example:
Add-RecipientPermission FaxService -AccessRights SendAs -Trustee John
Note: In case that you need additional information about how to use the PowerShell for Office 365, you can read the following article:

2. Add additional Email address (Alias)
The other option that we can use (instead of the security/distribution group solution) is: add the email address that will be used by the LAN Mail enabled Devices/Applications as an additional email address (Alias) for the recipient who is used by the IIS SMTP Server.

In our example, we will add two additional email address to the recipient named: John
Log in to Office 365 portal, in the Admin menu choose the option: Exchange
In the Exchange admin center choose the recipient menu –> mailboxes
Choose the recipient name that is used by the IIS SMTP Server (in our example: John).
Add additional Email address( Alias) -01
Click on the “add” option
In the Mailbox properties choose the option: Email address.
In our example, we will add to “John Mailbox” additional two email addresses (Alias): FaxService@o365info.com and HelpDesk@o365info.com
Add additional Email address( Alias) -02


Source:
Want to print your doc?
This is not the way.
Try clicking the ⋯ next to your doc name or using a keyboard shortcut (
CtrlP
) instead.