Exchange 2010 blocking RTF attachments

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Our accounting program’s sends reports as a .RTF file attachment which Outlook blocks. Making registry changes hasn’t made any difference. I was hoping to find a way to correct this now that I have everyone moved to a new mail server but haven’t found it yet. Isn’t there something I can do on our Exchange 2010 to lift the ban on .RTF file attachments?

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By default .RTF files are NOT blocked by Outlook 2010. See Attachment file types restricted by Outlook 2010 for the default list of blocked types and Plan attachment settings in Outlook 2010 for information on managing the blocked types. Also, see Attachment file types blocked by Outlook – Outlook – Microsoft Office.

For Exchange 2010 see Understanding Attachment Filtering and Configure Attachment Filtering.

Joe

--Joe

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I know they’re not on the list but they are being blocked just the same. “Outlook blocked access to the following potentially unsafe attachments: omega.rtf.”

What happens is the accounting program has an option to print to email and when you select that it opens a new blank email with the attachment omega.rtf only the attachment is blocked. I notice that there’s something called “ommapi” in the taskbar when this happens. It won’t let me access to view what it is. It goes away when the email is closed.

I’ve tried the registry tweaks found all over the Internet but they didn’t work. I tried group policy to permit RTF files and it didn’t make any difference either.

I’ll go back to the accounting vendor and complaint some more to them. It makes no sense really. The files really are RTF docs.

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Did you check the Exchange articles and settings?

Perhaps there is a policy being pushed that overrides your registry changes.

Joe

--Joe

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Have you tried creating a simple RTF file using Wordpad and attaching that to an email to see if that is blocked? If so, then the accounting software is doing something funny in trying to send to email. If you can’t attach that basic of an RTF doc, then Outlook is probably the program blocking it and not necessarily Exchange.

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I apologize for not responding to this sooner. I went on a long holiday in mid-December to care for a sick relative and promptly forgot after my return. The problem is now solved. This is what I learned and how I solved it.

Turned out the problem wasn’t just with the one person in accounting. I could replicate it on other computers, in ways not associated with the accounting program. For most tests, I used my personal Gmail account to send a small RTF file to my office email address. We were also unable to attach RTF files to emails created in office with Outlook 2003 or 2007.

We use Exchange 2010 setup with simple Hub Transport role which means the links above weren’t help as they related to the Edge Transport role and it’s Attachment Filter abilities.

We use Script Logic Desktop Authority for managing computers via login scripting. I tried pushing various combinations of group policies including Microsoft Office Outlook 2007SecuritySecurity Form SettingsAttachment Security to either limit or disable Level 1 and Level 2. This made no difference.

I also installed the Group Policy Management console on a domain server so I could find and examine all policies in play. None of them related to Office or Outlook. We’ve always managed those with the login script software but I had to look there to rule it out, of course.

I eventually found a registry value that was blocking the RTF files and used the login scripting to delete it. It was Level1Add located at HKCUSoftwarePoliciesMicrosoftOffice12.0OutlookSecurity Deleting that value solved it. No idea how the heck that setting made it into the registries. I didn’t know about the Level 1 or Level 2 security options until looking for the solution.

My luck, the accounting software upgrade scheduled to occur in five weeks will probably eliminate RTF files all together, but there had to be a solution because this didn’t just effect that small department. Thank you for your patience and advice. It was very much appreciated.

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I eventually found a registry value that was blocking the RTF files and used the login scripting to delete it. It was Level1Add located at HKCUSoftwarePoliciesMicrosoftOffice12.0OutlookSecurity Deleting that value solved it. No idea how the heck that setting made it into the registries. I didn’t know about the Level 1 or Level 2 security options until looking for the solution.

I’ll take a wild guess that there was a major security issue with RTFs at some point, so someone applied a FixIt to those users and then forgot to remove it once the vulnerability was patched.

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FWIW, if you have a simple Exchange server setup (i.e. one server, no edge server) most of the information about edge servers applies to your server since it really has edge server responsibilities too. The problem is figuring out which of the “most” is which. :rolleyes:

BTW, glad you solved it. Outlook & Exchange can be most challenging.

Joe

--Joe

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