Inline UUEncoded attachments of email messages from a UNIX-based application are garbled or are unreadable

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Article ID: 2590107 - View products that this article applies to.
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Consider the following scenario:
  • A user receives an email message from a UNIX-based application.
  • The email message contains an inline UUEncoded attachment.

In this scenario, the attachment is garbled or is unreadable. Additionally, the attachment is displayed as the following picture in the email message body:

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A sreenshot of email message body

Note The following content is displayed in an affected message header.

MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"


This issue occurs because of "begin 664." This indicates that UUEncoding is being used. When an email message contains an inline UUEncoded attachment, multipart MIME instead of MIME should be used. Otherwise, Microsoft Exchange translates the UUEncoded data as a part of the message body that has a MIME designator. 


To resolve this issue, encode the message by using multipart MIME. 

Note The issue cannot be resolved on an Exchange server because Exchange displays the messages according to the specified MIME encoding type.

More information

For more information about MIME, visit the following website:

General information about MIME


Article ID: 2590107 - Last Review: December 10, 2013 - Revision: 4.0
Applies to
  • Microsoft Exchange Server 2010 Enterprise
  • Microsoft Exchange Server 2010 Standard
  • Microsoft Exchange Online
  • Microsoft Business Productivity Online Dedicated
  • Microsoft Business Productivity Online Suite Federal
vkbportal226 kbgraphic KB2590107

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