I recently implemented a Barracuda Spam and Virus Firewall 300 at a business. The configuration was easy enough as they had an Exchange 2010 environment. Having a similar live system at my own company made it even easier as I could just walk through it tab by tab and essentially duplicate the settings I had on my existing system.
The implementation from out of the box to installed and filtering took about three hours. Everything looked great. Or so I thought...
As usual with these type of things, the unexpected always rears it's ugly head. This time it was several days after initial implementation. People we complaining about two things: 1) their quarantined mail didn't have nearly as many items in it as their old system (Postini by Google) and 2) some emails were taking up to eight hours to be delivered.
This first issue they raised was a simple explanation: the Barracuda simply was filtering them out rather than quarantining them. I asked them if they wanted me to dial back the filtering to have it put more in the quarantine rather than outright blocking it. "No, no..." they said "we hated all those emails in there. We just didn't know where they went."
The second issue was a bit trickier. I started looking at the logs and the queues and the Advanced Queue management and sure enough some emails would be queued for delivery but would never make that last jump over to the Exchange server.
Now this Exchange server is nothing special, but it is probably overkill for this company's purposes. It is on a HP Proliant DL380 Gen 5 with 16 GB or RAM and dual processors. Not a monster, but with only ten users, more than enough horsepower to suffice.
I contacted Barracuda support and they told me that the spam filter was having issues connecting to the Exchange server and at times it looked like it wasn't even getting an SMTP connection.
I proceeded to go about applying all software updates and firmware patches on as well as the latest device drivers. No dice. Still had the issue.
They I replaced the NIC cards, the switch and the cables going from the server to the switch and the Barracuda to the switch. Still nothing.
At this point, I talked to Barracuda again and told them that I had pretty much replaced everything I could from a network standpoint, but I was not convinced that it wasn't an issue with the Barracuda Unit. They shipped me another one and I had it the next day. Applied some firmware updates on the new unit, transferred the configuration and....nothing. Same problem.
So back to the drawing board I went. I started to do research the SMTP connector on Exchange 2010. After a few hours of searching, I hit pay dirt. I opened the Exchange Management Shell (EMS) and typed the following:
Get-ReceiveConnector -Identity "Default <Servername>" | fl
It then proceeded to list several key pieces of information. The based on the research I did, I changed the following settings:
Set-ReceiveConnector -Identity "Default <Servername>" -ConnectionTimeout 00:10:00
Set-ReceiveConnector -Identity "Default <Servername>" -ConnectionInactivityTimeout 00:10:00
Set-ReceiveConnector -Identity "Default <Servername>" -Banner "220 SMTP OK"
These ccould actually be combined to the following:
Set-ReceiveConnector -Identity "Default <Servername>" -ConnectionTimeout 00:10:00 -ConnectionInactivityTimeout 00:10:00 -Banner "220 SMTP OK"
So I applied these settings and went back to my Barracuda and checked the queue....and I waited.
And nothing happened. The mail sailed right through just like it should. Problem solved.
Hopefully someone else will find this information useful and won't have to jump through all the hoops I did.