Configure Mail Server

Setting up connectors, transport rules, and special headers like the X-Conbool Header is a key part of configuring your email flow. The setup is explained below using Microsoft Exchange as an example. This process can be similarly applied to other mail servers.

Why is this important?

• Secure Message Flow: Connectors enable secure communication between your system and external email servers.
• Efficient Processing: Transport rules automate the handling of messages based on defined criteria.
• Message Integrity: The X-Conbool Header ensures that important metadata is preserved during processing.

Step-by-Step Setup Guide

1. Create Connectors

Connectors manage the mail flow between your Office 365 environment and external services like Conbool. We need two connectors: one for inbound emails from Conbool and one for outbound emails to Conbool.

Navigation: In the Microsoft 365 Admin Center, go to Exchange admin center → Mail flow → Connectors.

A. Inbound Connector (From Conbool)

This connector allows Conbool to send emails to your organization.

1. Add connector: Click + Add a connector.
2. Connection from: Select Partner organization.
3. Connection to: Is automatically set to Office 365. Click Next.
4. Name: Enter From Conbool. Click Next.
5. Authenticating sent email: Select By verifying that the IP address of the sending server matches one of these IP addresses that belong to your partner organization.
6. Add IP address: Enter the IP address 217.160.214.251 and click the + symbol.
7. Click Next.
8. Security restrictions: Enable the option Reject email messages if they aren't sent over TLS. This ensures only encrypted connections from Conbool are accepted.
9. Click Next.
10. Review: Review the summary and click Create connector.

B. Outbound Connector (To Conbool)

This connector routes emails from your organization to Conbool via a transport rule.

1. Add connector: Click + Add a connector again.
2. Connection from: Select Office 365.
3. Connection to: Select Partner organization. Click Next.
4. Name: Enter To Conbool. Optionally, add a description. Click Next.
5. Use of connector: Select Only when email messages are sent to these domains is the typical choice, but based on your previous German text and the screenshot rule which uses redirection, the more precise setting might be Only when I have a transport rule set up that redirects messages to this connector. Select the option that aligns with how you intend to use it, the transport rule method is specified below. If using the transport rule method, no domains are needed here. If using smart hosts directly:
6. Routing: Select Route email through these smart hosts.
7. Add smart host: Enter the IP address 217.160.214.251 and click the + symbol.
8. Click Next.
9. Security restrictions:
   • Ensure Always use Transport Layer Security (TLS) to secure the connection is enabled.
   • For Connect using: Select Issued by a trusted certificate authority (CA). (Standard and usually appropriate).
   • Click Next.
10. Validation email: Enter an external email address (e.g., your own at another provider) to validate the connector and click +. Then click Validate.
    • Note: Validation might fail because the transport rule (which adds the X-Conbool header) is not yet active, or the Conbool server handles the validation email differently without this header. This is often not a critical issue for functionality. You can usually proceed even if validation reports an error.
11. Review: Review the summary and click Create connector.

2. Define Transport Rule ("Relay to Conbool")

This rule determines which emails should be routed to Conbool and adds the necessary X-Conbool header.

Navigation: In the Exchange admin center, go to Mail flow → Rules.

1. Create a new rule: Click + Add a rule and select Create a new rule.
2. Name rule: Give the rule the name Relay to Conbool.
3. Apply this rule if... (*):
   • Select the condition(s) that determine which messages should be routed via Conbool.
     • Example from screenshot: Apply to all messages (Adjust this to your specific needs, this is often too broad!).
     • Typical conditions:
       • The sender is located... → Outside the organization.
       • The recipient is located... → Outside the organization.
       • The sender is a member of... → (A specific group of users).
   • Important: Define precisely which emails should be affected here!
4. Do the following... (*):
   • Action 1 (Redirect):
     • Select Redirect the message to... → the following connector.
     • Choose the previously created connector To Conbool and click Save.
   • Action 2 (Add Header):
     • Click + Add action.
     • Select Modify the message properties... → set a message header.
     • Click the first link (Enter text) and set the message header name to: X-Conbool
     • Click the second link (Enter text) and set the header value to: conbool.com
     • Click Save.
5. Except if... (*):
   • It is crucial to add an exception to prevent mail loops where Conbool sends an email back, and it gets redirected again.
   • Click + Add exception.
   • Select The sender... → IP address is in any of these ranges or exactly matches.
   • Enter the IP address of Conbool: 217.160.214.251.
   • Click Add and then Save.
6. Review rule settings:
   • Check the other settings (e.g., Priority, Mode). Ideally, start in Test without Policy Tips mode before setting the rule to Enforce.
7. Save: Click Next through any remaining steps, then click Finish or Save.
8. Enable: Ensure the rule is enabled (checkmark in the rule list).

Summary & Next Steps:

• You have now created an inbound connector (From Conbool) and an outbound connector (To Conbool).
• You have defined a transport rule (Relay to Conbool) that:
  • Selects emails based on your criteria.
  • Redirects these emails via the To Conbool connector.
  • Adds the X-Conbool: conbool.com header.
  • Prevents emails already coming from Conbool (based on IP 217.160.214.251) from being redirected again.

Additional Notes

• Configuration may vary depending on the system (e.g., Microsoft Exchange, Sophos Gateway). Ensure that all settings are regularly reviewed and updated.