Exchange On-Premises
Mail server variant for a local Exchange server, version 2016 or later. Send/Receive Connector and transport rules in the Exchange Admin Center.
Prerequisite: Step 1, Domain & DNS Setup is complete and all four DNS checks are green.
What happens here: A Send Connector, a Receive Connector, and two transport rules are created in the local Exchange Admin Center. In the Setup Assistant, the Manual configuration mode is chosen.
Effort: 30 to 45 minutes.
Step A. Send Connector
Navigation: Exchange Admin Center (On-Premises) → Mail flow → Send Connectors → new Send Connector
| Field | Value |
|---|---|
| Name | Conbool Outbound Connector |
| Type | Custom |
| Address space | * for all domains, or specific domains |
| Smart host | mail.conbool.com |
| Smart host authentication | None, authentication is handled via TLS certificate |
| Require TLS | Enabled, domain validation against mail.conbool.com |
| Use MX Record | No |
| Source server | Hub Transport server that should use the connector |
Create and enable the connector.
Step B. Receive Connector
Navigation: Exchange Admin Center (On-Premises) → Mail flow → Receive Connectors → new Receive Connector on the respective server
| Field | Value |
|---|---|
| Name | Conbool Inbound Connector |
| Type | Partner |
| Network adapter bindings | Leave default, all available IPs on port 25 |
| Remote IP ranges | Conbool IP addresses, provided by Conbool |
| Require TLS | Enabled |
| TLS Sender Certificate Name | mail.conbool.com |
| Restrict Domains to Certificate | Yes |
Create and enable the connector.
Firewall: Port 25 (SMTP) must be open from the Conbool IP addresses to the Exchange server.
Step C. Transport Rule "Relay to Conbool"
Navigation: Exchange Admin Center (On-Premises) → Mail flow → Rules → new rule
This rule routes outbound emails through Conbool and prevents loops.
- Name: Conbool Exchange transport rule
- Sender address location: Header or envelope
- Apply this rule if: The sender is located → Inside the organization
- Do the following: Route the message to the following connector → Conbool Outbound Connector
- Except if (add all four exceptions):
- A message header matches → Header:
X-Conbool-<YourDomain>(e.g.X-Conbool-example-com) → Pattern:true - The message type is → Calendaring
- A message header contains → Header:
Return-Path→ Words:<> - The sender address matches → Pattern:
<>
- A message header matches → Header:
- Priority:
0 - Mode: Enforce
- Save and enable.
Step D. Transport Rule "Classify Spam"
Navigation: Exchange Admin Center (On-Premises) → Mail flow → Rules → new rule
This rule sorts emails marked as spam by Conbool into the Spam folder.
- Name: Conbool Spam classification rule
- Apply this rule if: A message header matches → Header
X-Conbool-Flag→ PatternYES - Do the following: Modify the message properties → set SCL to
7 - Priority:
1 - Mode: Enforce
- Save and enable.
Done When
Back in the Setup Assistant at the Mail Server step. Enter the relay host of the Exchange server, typically the FQDN of the Hub Transport server, for example mail.yourcompany.local, then click Test Connection. Status "SMTP reachable" means the connection is established.
Continue with the connection test and completion.