Vanishing attachment content

Tickets created from email with attachments something like:

--------------080002000901040106020609
Content-Type: message/rfc822;
name="attachment.eml"
Content-Transfer-Encoding: base64
Content-Disposition: inline;
filename=“attachment.eml”

Received: …
x-mimeole: Produced By Microsoft Exchange V6.0.6603.0
content-class: urn:content-classes:message
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="----_=_NextPart_001_01C85484.BABB2102"
Subject: …
Message-ID: …
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
Thread-Topic: H8DA3-2 On-Board SAS Feature
Thread-Index: AchUbJG5vOK/tePKTaKLVSrvzFFIowAFYhCg
From: …
To: …
Cc: …
X-SpamReason: Bypass=B

VGhpcyBpcyBhIG11bHRpLXBhcnQgbWVzc2FnZSBpbiBNSU1FIGZvcm1hdC4NCg0KLS0tLS0t
Xz1fTmV4dFBhcnRfMDAxXzAxQzg1NDg0LkJBQkIyMTAyDQpDb250ZW50LVR5cGU6IHRleHQv
cGxhaW47DQoJY2hhcnNldD0idXMtYXNjaWkiDQpDb250ZW50LVRyYW5zZmVyLUVuY29kaW5n
OiBxdW90ZWQtcHJpbnRhYmxlDQoNCkhpIENhcm9saW5hLA0KDQo9MjANCg0KVGhlIFBDSS1F

are not only not decoded inline, but the content has vanished. The
header shows up, but I can’t even view the encoded data. Is there a
problem with base64 decoding? Any suggestions?

Thanks,
Justin