Scenario:

When we receive inbound AS2 traffic from our AS2 partner, we are looking to preserve the original filename that was sent from the trading partner.

The actual filename value can be found in the AS2 header section

Email Notification Error Message:

The following transaction produced a warning on 01-22-2015 14:17:00:
Session ID: 160445
Details: Filename preservation is required, but the received document was not named.: Document will not be published to any inbound channels.

Resolution:

Due to the trading partner not sending the filename, in the AS2 envelope, we need to disable the "Preserve Filename" option.