Email mail flow chart:
Barracuda Cloud Protection -> WatchGuard Firebox Router -> Barracuda Anti-Spam Firewall -> Exchange 2010 Server
User reports that a recent email was stripped of 2 Excel attachments by the WatchGuard Router, and in it's place were couple of TXT files explaining what was stripped.
I research the issue and adjust the WatchGuard router to allow the Excel attachments.
I access Barracuda Cloud Protection, find the email with Excel attachments and successfully initiate a re-deliver, but email never gets to the end users Exchange mailbox.
I search Barracuda Anti-Spam logs and can see the email was received with Excel attachments, thus confirming the changes to the WatchGuard worked, and did not strip the files. I then re-deliver using the Barracuda Anti-Spam, but still email does not reach end user.
I use Exchange 2010 tracking log explorer and search for the emails and discovery the re-deliveries are being received, but treated as duplicate. I tried to delete the first email that was stripped by the WatchGuard, but another re-deliver still gets treated as a duplicate and will not appear in Exchange users mailbox.
Is there a way for Exchange 2010 to deliver the duplicate to the mailbox?
I will probably advise the user to request a resend of the email, but I would like to know if there's something I can do in the future if I run into a similar situation.