Recently in our domain with Exchange 2007 and using Outlook 2007 we are seeing randomly an issue which involves pdf attachments. Clients send our users an email with pdf attachments and the users can see the paperclip indicating that there is an attachment but when the email is opened up it does not show the attachment. In one instance if you save the email and check the file size it is 1 MB so it is definitly carrying the attachment. If the open the email in Outlook Express the attachment is there and it will open. If you check OWA in Internet Explorer 8 the attachment is there but it gives an error of "Internet Explorer cannot download attachment.ashx from web.company.com (where company is our company name). Internet Explorer was not able to open this Internet site. The requested site is either unavailable or cannot be found. Please try again later." When we try OWA from Chrome the attachment will open up fine.
When you forward the message to an outside email address and they recipient opens the email they can see the attachment.
We go through postini for spam protection.
As I said this is a random issue but it seems to be happening more and more and really turning in to an issue.
Any help would be appreciated.