Content Type Problem

[airbourne]

Ok, I can't seem to find this problem described anywhere. Here's the scenario:

A user from CompanyA sends an email to a user in CompanyB. The user in CompanyA attaches a PDF document that is not in any way corrupted.

The user in CompanyB checks her email using OWA 2003. She is unable to view or download the PDF attachment. If that same user in CompanyB checks her email using an OUTLOOK client, the PDF attachment opens or saves just fine.

I know what is wrong, I just don't understand why: When the email arrives from the user in CompanyA, a review of the message header reveals:

------_=_NextPart_001_01C84195.DB84BD82
Content-Type: text/html;
name="findclaim.pdf"
Content-Transfer-Encoding: base64
Content-Description: findclaim.pdf
Content-Disposition: attachment;
filename="findclaim.pdf"


If I download the PDF attachment to my computer (using an Outlook Client) and compose a brand new email and attach that very same PDF, and send it, the message header is this:


------=_Part_1381_32963440.1198331233377
Content-Type: application/pdf; name=findclaim.pdf
Content-Transfer-Encoding: base64
X-Attachment-Id: 0.1
Content-Disposition: attachment; filename=findclaim.pdf


If I compose a message using my GMAIL account and attach the PDF, the message header Content-Type is also "application/pdf" (which is what I would always expect to see).

My question is this: Why does CompanyA attach this message as the wrong Content-Type? I have tried to duplicate the problem, but I cannot. It only seems to be emails coming from CompanyA that have this Content-Type mismatch.

Because the Content-Type is wrong, the browser (IE, firefox, etc.) tries to process the attachment as a web page. If you view the message by clicking, a web window pops up with garbage text. If you try to right-click and save target as, it saves the file as HTM or HTML. If you rename the file back to PDF, the file is not viewable. The file is getting corrupted during the save as HTML.

The outlook client seems to ignore the Content-Type mismatch and process the file based on it's actual name "findclaim.pdf".

Is it their server that has the Content-Type mismatch? I'd like to understand this issue to make sure it's not me making the mistake before I go back to CompanyA and let them know of the problem.

Please help!

 

[58sniper]

Do they have some AV solution that's causing it?

Pat Richard
Microsoft Exchange MVP

 

[airbourne]

I gave up trying to discover the problem. I contacted their IT department and told them they are attaching PDF files as the wrong content type. We'll see where that goes.

 

[airbourne]

Quick update, this problem *IS* a problem with their server, but they are unwilling to change it. They use a hosted solution to filter their outgoing email messages, but were also unwilling to divulge who.

Either their server or this hosted filtering solution is the cause of the problem, but they see it as our problem because we use OWA and none of their other clients do.

Such is life I suppose. We've been able to create an internal process to make the problem more of an annoyance rather than a show stopper.

 

[Zelandakh]

Sounds like either a digital certificate sort of issue or more likely a MIME encoding issue.

Either way you can't get round it.

 

[airbourne]

I suspect the MIME encoding issue. Is that something this vendor could fix if they wanted to?

I'm still at a loss as to why they are sending emails this way. I've never experienced this behavior with any of the mail systems I have ever worked with.