FIX: "The message content has become corrupted" exception when email contains a UUE-encoded attachment in Exchange Server 2016

Applies To

Exchange Server 2016 Enterprise Edition Exchange Server 2016 Standard Edition

Symptoms

In a Microsoft Exchange Server 2016 environment, the Transport service may not send email messages that contain an attachment that was encoded with Unix-to-Unix Encoding (UUE) type. When this issue occurs, you experience the following exception:

Note

554 5.6.0 Corrupt message content
STOREDRV.Deliver.Exception:ConversionFailedException.ByteEncoderException;
Failed to process message due to a permanent exception with message. The message content has become corrupted.

Cause

This issue occurs because the UUE attachment size exceeds the defined MaximumBytes of the Transport's UUDecoder.

Resolution

To resolve this issue, install Cumulative Update 5 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.

Status

Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.

References

Learn about the terminology that Microsoft uses to describe software updates.