We host a website for people to sign-up for events and athletic teams/sports. When people sign-up for said sport, an email is sent to that individual with a PDF attachment which is their receipt. If the person receives the email, the PDF opens just fine and all is right with the world. If the email is returned to us (invalid email, mailbox full, etc) the PDF is corrupt and we can't open it to print it to snail mail the receipt to the individual.

This occurs across multiple domains: Gmail, Yahoo, Hotmail, Comcast, AOL, Verizon, et al

Now, our website is setup to send email out directly through one of our Barracudas (Spam and Virus Firewall 300) and doesn't touch our Exchange (2007) setup at all. The email only touches Exchange should it be returned for whatever reason. Attachments can't be opened via OWA or Outlook (this was tried across multiple machines).

Opening a returned email brings up an error indicating a corrupt PDF file. I have tried running a PDF "Fixer" on some of these receipts to no avail - the PDF "Fixer" actually says there are no page numbers in the file. Also, one of our network guys noticed the files which leave are almost twice as large as the files which are attached if the email should get returned.

It's almost as if something is stripping code from the PDFs.

I'm at a loss.

Suggestions?

Yes. You need someone to follow the trail of a pdf and find out what is getting messed with.

Someone that knows about the beast Exchange. things to check are encoding setups all the way through, and clients as well.

check your receive / send connectors. make sure these setting are all checked and set appropriately.

check the header for what the encoding is:
Content-Transfer-Encoding: uuencode
Content-Transfer-Encoding: base64

make sure there is nothing there out of place.


You have applied all patches/updates to exchange, the OS's and the clients, as well as the security software?

one issue I encountered was related to base64 decoding, and it was the Outlook clients corrupting while decoding the attachment. it would get to a CR and start filling the .pdf with blanks, or truncate file right there. have a look in a hex editor at one of the corrupted files. Cant remember which versions it was though.

I am leaning against it being anything to do with the sec software, and toss-up between, the outlook client, second a dodgy setup somewhere.

Really really hard to figure these out without just sitting down at a console and going through it.

good luck