Email duplicated from Barracuda Cloud Layer
February 26, 2014 7:18 AM Subscribe
Some email to our server is being duplicated from the Barracuda Cloud Layer to our local Barracuda 300. Barracuda support says there are routing and latency issues. I don't see the evidence but not sure how to resolve it. Details inside...
posted by dukes909 to Computers & Internet (7 answers total)
Incoming email to our domain first goes to the Barracuda Cloud Protection Layer before being passed to our local Barracuda 300 antispam appliance. It then goes to our email server (CommuniGate). Approximately 1 week ago users started getting duplicates of email. For example, a user receives an email at 10am. Then they might receive the same email again at 10:02, 10:10. It is not not specific to any single domain. It does not occur for all inbound emails. It never occurs for email within our local domain (not process by Barracuda CPL).
I opened a call with Barracuda and they confirmed emails were being resent from the CPL to the local Barracuda but could not provide an explanation other than several messages were getting a "Deferred 451 No HELO/EHLO" status. They did a packet capture on the local Barracuda device and says there a lot of TCP retransmission packets coming from the barracuda cloud control servers to our local Barracuda. Additionally they say there is a routing issue based on this traceroute and want me to take it up with AT&T.
[firstname.lastname@example.org] # traceroute 188.8.131.52
traceroute to 184.108.40.206 (220.127.116.11), 30 hops max, 40 byte packets
1 99-72-249-174.uvs.mmphtn.sbcglobal.net (18.104.22.168) 2.628 ms 1.739 ms 1.810 ms
2 * * *
3 * * *
4 * 22.214.171.124 (126.96.36.199) 29.625 ms 26.311 ms
5 * * *
6 188.8.131.52 (184.108.40.206) 32.062 ms 31.286 ms 29.848 ms
7 220.127.116.11 (18.104.22.168) 152.513 ms 156.651 ms 96.317 ms
8 22.214.171.124 (126.96.36.199) 87.976 ms 85.129 ms 86.262 ms
9 oak1-ar1-xe-1-0-0-0.us.twtelecom.net (188.8.131.52) 95.168 ms 94.619 ms 108.430 ms
10 126.wecare.net (184.108.40.206) 100.729 ms 100.566 ms 100.232 ms
11 mail14.ess.barracuda.com (220.127.116.11) 100.931 ms 100.411 ms 100.244 ms
They also suggested I change the DNS server setting on the local Barracuda to something other than OpenDNS servers, but added they didn't think this was this issue and gave no alternative.
I'm sort of at a loss at what to do now. Does it really look like a routing issue?