There is a work around on the Ironport MTA server:
1. Hover mouse over Network
2. Select Listeners from the drop down menu.
3. Select VontuToIronport listener
4. Expand Advanced, by selecting it.
5. In the CR and LF handling section you need to select Allow messages with bare CR and LF characters. The default is Clean messages of bare CR and LF characters.
Applies To
This may occur with an Ironport MTA with TLS Encryption Enabled.