smtp.mailchannels.net as a smart host, authenticates using your MailChannels SMTP credentials over TLS, and applies to all external recipient domains. This guide covers Exchange 2016 and 2019, which share a nearly identical configuration workflow through the Exchange Admin Center (EAC).
These instructions apply to Exchange 2016 and Exchange 2019. If you are running Exchange 2010, the configuration is done through the Exchange Management Console rather than the EAC. See the Exchange 2010 note at the bottom of this page.
Prerequisites
- Administrator access to the Exchange Admin Center
- Your MailChannels SMTP username and password
- A working Exchange server configured for client access and able to route messages to the internet
Configure the Send Connector
Open the Send Connectors list
Log in to the Exchange Admin Center (EAC).
- Exchange 2016: Access the EAC at
https://localhost/ecpfrom the Exchange server, orhttps://<ServerFQDN>/ecpfrom another machine. - Exchange 2019: Access the EAC from the Exchange Admin Center in your browser.
Name the connector and set the type
Enter a descriptive name for the connector — for example, MailChannels-Relay or MC.For Type, select Internet. This grants the connector the default permissions required to route messages through an external host outside your domain forest.Click Next.
Configure smart host routing
Select Route mail through smart hosts, then click Add (+).In the Add smart host dialog, select Fully qualified domain name (FQDN) and enter:Click Save, then click Next.
Set authentication and TLS
On the smart host authentication page, select Basic authentication and check the box labeled Offer basic authentication only after starting TLS.Enter your MailChannels SMTP credentials in the Username and Password fields.Click Next.
Set the address space
In the Address space section, click Add (+). In the Add domain dialog, enter the following:
Using
| Field | Value |
|---|---|
| Type | SMTP |
| Fully Qualified Domain Name (FQDN) | * |
| Cost | 1 |
* as the FQDN means this connector applies to all external recipient domains. A cost of 1 makes this the preferred route.Click Save, then click Next.Add the source server
In the Source server section, click Add (+). In the Select a Server dialog, select the Mailbox server that will route mail through MailChannels.Click Add, click OK, then click Finish.
Send a test message
Send a test email from an account on your Exchange server to an external address (for example, a Gmail or Outlook.com account) to confirm that the connector is working. Log in to your MailChannels Host Console and check Activity > LogSearch to verify that the message was received and processed.
Alternate SMTP ports
MailChannels accepts connections on multiple ports. If outbound TCP port 25 is blocked by your network or ISP, configure your Send Connector smart host to use one of the following alternatives:| Port | Use case |
|---|---|
| 25 | Default SMTP |
| 587 | SMTP submission (commonly allowed) |
| 465 | SMTPS (implicit TLS) |
| 2525 | Alternate if 25 and 587 are both blocked |
smtp.mailchannels.net:587.
Exchange 2010
Exchange 2010 uses the Exchange Management Console rather than the web-based EAC. The setup follows the same general approach — create a new Send Connector with type Internet, set the smart host tosmtp.mailchannels.net, and enable Basic Authentication over TLS with your MailChannels credentials — but the steps are navigated through the console UI under Organization Configuration > Hub Transport > New Send Connector.
Exchange 2010 reached end of life in October 2020 and is no longer supported by Microsoft. Adding
X-AuthUser headers in Exchange 2010 requires building a custom transport agent using an SDK that Microsoft has since retired. If you are running Exchange 2010 and need help configuring it to work with MailChannels Outbound Filtering, contact MailChannels support and include the Exchange version in your request.