Inbound connector: FAQ
Summary: This article covers the most common questions asked by the customers and administrators about using Inbound connectors in Exchange Online.
For Exchange Online customers (any Office 365/Microsoft 365 customers using Exchange Online), the following document states best practices related to transport connectors. For more information, see Configure mail flow using connectors in Exchange Online.
The Inbound connector of OnPremises type can be created in the following ways:
Within the Exchange Admin Center in Exchange Online, it's defined as follows:
From: Your on-premises email server
To: Office 365
When you use a PowerShell cmdlet
New-InboundConnector, use parameter
When Hybrid Configuration Wizard (HCW) is run on-premises, the connector is named as
Inbound from <TenantGUID>, and
ConnectorSourceparameter is set as
ConnectorTypeparameter is set as
The purpose of an Inbound connector of OnPremises type is for our customers that are still in Hybrid mode. To send emails from their mailboxes hosted within on-premises environment to mailboxes hosted in the Exchange Online service.
In addition, we do provide support for on-premises mailboxes to relay emails to the Internet via Exchange Online. Inbound connectors of OnPremises type aren't designed to relay bulk emails to the internet; hence any such activity is a misuse of the feature.
When you create an Inbound connector of OnPremises type, you may see the warning message:
"Inbound connector for this service offering is created in a disabled state. Contact Support to enable it."
When you update an Inbound connector of OnPremises type, you may see the warning message:
"For this service offering, you can't enable an inbound connector. Please contact Support to enable it."
If this happens, do the following:
Read the below FAQ and document listed above to understand whether or not you need an Inbound connector of OnPremises type.
If your organization does need to create an Inbound connector of OnPremises type, contact Microsoft Support with your business justification. Our service engineers then approve the legitimate usage and enable the connector.
Q: When do I need to create an Inbound Connector of OnPremises type?
You usually don't need to create an Inbound Connector of Onpremises type. See Configure mail flow using connectors in Exchange Online for guidance.
Q: I'm using a third party filtering service to filter emails from the internet for my organization. Do I need to create an Inbound Connector of Onpremises type?
No, you don't need to create an Inbound Connector of Onpremises type. As long as the configuration in the third party service delivers the messages using your organization’s .onmicrosoft.com domain, your mail is successfully delivered.
Q: I'm using a third party add-on service to process emails that are composed by users of my Exchange Online organization before they're sent to the internet. I need to create an Inbound connector of OnPremises type to relay emails from the third party service for my organization. What do I need to do?
It's a valid scenario of using Inbound connector of OnPremises type. Follow the instructions as mentioned in Scenario Integrate Microsoft 365 or Office 365 with an email add-on service.
In Step 4, if you're using PowerShell cmdlet
New-InboundConnector to create a connector, ensure
SenderIPAddresses is empty. Only a unique certificate domain from the third party service is allowed and the domain must be an accepted domain in your organization. If your organization provides the add-on service and your customers followed the instructions but still see a warning message, contact Microsoft support to address the issue.
Q: Why do I see a warning message “Inbound connector for this service offering is created in a disabled state. Contact Support to enable it.” when I try to create an Inbound Connector of OnPremiseType? What should I do, if my organization needs to create an Inbound Connector of OnPremises type?
These connectors are created as “Disabled” by default. Customers that experience this behavior must contact Microsoft support with a business justification to enable an Inbound connector of OnPremises type within their tenant.
Q: I'm running HCW(Hybrid Configuration Wizard) and I see a warning message “Inbound Connectors created by HCW are in disabled state”? What do I need to do to enable the Inbound Connector by HCW?
In connectors created via EAC (Exchange Admin Center) or PowerShell cmdlet, customers that experience this behavior must contact Microsoft support. With a business justification to, enable an Inbound connector of OnPremises type for hybrid use within their tenant.