Setting up MPMail Lockdown Rules using Powershell

Description

This article describes how to set up the MPMail mail flow rules using powershell

Requirements

• A global admin account in the Microsoft 365 tenancy

The Process

• Open powershell and connect to exchange online with the following command: Connect-ExchangeOnline
• Enter global admin credentials
• Once authenticated and connected, enter the following command to create the MPMail Inbound rule:

New-TransportRule "MPMail Inbound Rule" -ExceptIfFromScope InOrganization -RejectMessageEnhancedStatusCode 5.7.1 -RejectMessageReasonText "Email bypassed MXRecords" -ExceptIfSenderIpRanges 94.100.128.0/20,185.140.204.0/22,173.45.18.0/24,83.246.65.0/24,81.20.94.0/24,52.62.114.130,52.62.125.178,35.174.145.124,15.222.110.90,52.212.19.177 -ExceptIfMessageTypeMatches Calendaring

• Enter this command to create the rule that bypasses Microsoft Spam Filtering:

New-TransportRule "Bypass Spam Filtering" -SentToScope InOrganization -SetSCL -1

• You can also create the connector but it will still need to be validated. To create it, use the following command. Note to substitute the actual domain instead of <domain> below.

New-OutboundConnector -Name "MPMail Outbound" -Comment "Send all external outbound email through MPMail SmartHost" -Enabled $true -RecipientDomains * -SmartHosts <domain>.outbound.anz.mpmailmx.com -TlsSettings EncryptionOnly -UseMXRecord $false

1. To validate the connector, use the command below or do it via M365 Exchange Online admin center under Mail Flow/Connectors

Validate-OutboundConnector -Identity "MPmail Outbound" -Recipients <enter external email address>