Scenario
Latest update: Microsoft released an update for Outlook 2010 in August that resolves the issue.The August 11, 2015 update for Outlook 2010 (KB3055041) was intended to resolve an issue where attachments may be lost, but for many of our clients, installing this update was the first time such issues had been observed. These changes have been included in subsequent updates for Outlook 2010 from August 2015 to July 2016. The August 9, 2016 (KB3115474) update includes a fix that resolves the issue.
In Outlook 2013, this issue was first observed after installing the September 8, 2015 update (KB3085495). The changes were included in subsequent updates for Outlook 2013 from September 2015 to May 2016. The June 7, 2016 (KB3115158) update includes a fix that resolves the issue.
Affected updates
Microsoft Office 2010
- KB3055041 (Aug 2015)
- KB3085522 (Sep 2015)
- KB3085604 (Oct 2015)
- KB3101535 (Nov 2015)
- KB3114409 (Dec 8 2015)
- KB3114560 (Dec 16 2015)
- KB3114570 (Jan 2016)
- KB3114756 (Feb 2016)
- KB3114883 (Mar 2016)
- KB3114996 (Apr 2016)
- KB3115127 (May 2016)
- KB3115247 (June 2016)
- KB3115246 (July 2016)
Microsoft Office 2013
Resolution
Microsoft Office 2010
Microsoft Update
Use Microsoft Update to automatically download and install the update. For more information about how to get security updates automatically, see the "Turn on automatic updating in Control Panel" section of this Safety & Security Center article.
Microsoft Update Catalog
To get the stand-alone package for this update, go to the Microsoft Update Catalog website.
Download Center
You can get the stand-alone update package through the Microsoft Download Center. Follow the installation instructions on the download page to install the update.
- Download the security update KB3115474 for the 32-bit version of Outlook 2010
- Download the security update KB3115474 for the 64-bit version of Outlook 2010
Microsoft Office 2013
Microsoft Update
Use Microsoft Update to automatically download and install the update.
Download Center
This update is also available for manual download and installation from the Microsoft Download Center. The updates in the Download Center can't be installed on Office Home and Student 2013 RT.
- Download update KB3115158 for 32-bit version of Outlook 2013
- Download update KB3115158 for 64-bit version of Outlook 2013
If you're not sure what platform (32-bit or 64-bit) you're running, see Am I running 32-bit or 64-bit Office? Additionally, see more information about how to download Microsoft support files.
Test the issue
Written steps
- Create a DOCX document and name it document1.docx
- Create a second DOCX document and name it document2.docx
- Create a MSG file and name it message1.msg
- Create a new email, add at least one recipient and a subject, and attach all three files (document1.docx, document2.docx, and message1.msg).
- Save your email using by selecting Save from the quick access toolbar (QAT), or wait for the email to autosave to your Drafts.
- Send the email.
- Go to the Sent Items. You may notice that the MSG file is missing or the files are renamed.
Video of the steps
We have seen the scenario above, but there may be similar instances with other attachments. For example, you may experience similar issues with Excel spreadsheets, PowerPoint presentations and other file types.