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Exchange Connector Overview

Exchange Connector downloads email messages from a POP3 server and forwards them to Exchange Server using SMTP. It is an entirely server-based product. The delivery mechanism is effectively transparent to both users and to Exchange Server.

Exchange Connector POP3 email delivery can be used as the exclusive delivery mechanism for inbound mail, or it can co-exist with other Receive Connectors in Exchange, including direct SMTP routing. Exchange Connector is completely transparent to Exchange server (it does not require any Transport Agents or special components, and it does not interact with Exchange APIs). Messages delivered by to Exchange by Exchange Connector appear the same as if they had been delivered via direct SMTP. This design enables all Exchange routing features, such as message filtering, transport rules and anti-spam agents, to be retained.

The simplest installation approach is to install Exchange Connector directly on a supported Exchange server. It is also supported to install Exchange Connector on a different server, as long as the required SMTP access to the Exchange Server is provided. Exchange Connector needs to be installed on a domain-joined machine on the same network segment as Exchange Server and Active Directory infrastructure. Workstation platforms (Windows 8 & Windows 10) are supported, but are only recommended for smaller installations (< 100 mailboxes).

In an environment with multiple Exchange Servers, the recommended approach would be to have a separate installation on each Mailbox server which downloads and delivers messages for the mailboxes stored on that server. Although it is possible to have a single instance of Exchange Connector for the entire Exchange environment, it needs to be understood that each installation of Exchange Connector will direct all messages it handles to a single Exchange Server. Internal routing in Exchange will automatically re-route messages destined for another server in this scenario, although redundancy would not be provided if the destination Exchange Server goes offline. Although directing messages to a DNS-based load balancer as the SMTP destination is supported, the typical use cases for Exchange Connector are not intended for a high-availability Exchange environment, as it is not supported to have more than one instance of Exchange Connector which connects to the same POP3 mailboxes.

Exchange Connector does not provide an outbound mail solution because this is already provided in Exchange Server. If your Exchange Server does not have a static IP address or is situated behind a restrictive external firewall, relaying outbound mail via another SMTP Server (sometimes referred to as a smart-host) is strongly recommended. This can be configured using a Send Connector in Exchange. For detailed instructions see the FAQ.