If you use EuropeanMX to filter both incoming and outgoing e-mails (using a smart host setup), all external SMTP communication is automatically archived as part of the domain for which archiving is enabled. However, Microsoft Exchange does not forward internal communication via the outbound smart host, so internal communication is not archived by default.
However, archiving internal communication is quite simple and can be done using the Exchange protocol system. The journaling system allows Exchange to automatically send a copy of all internal communications to an external e-mail address.
As long as you have configured the external e-mail address with EuropeanMX for archiving, the EuropeanMX input filter processes the message and archives it. Configure the destination address to which the journaling reports are sent as a recipient in the whitelist. This means that no filtering or delivery to an external server takes place for the received messages.
Activate journaling on your Exchange server and make sure that a copy of each e-mail is automatically sent to the archived recipient.