We have a Barracuda 300 on firmware version 5.1.2.006 and running Exchange 2010 on Server 2008 R2 for our domain. We are having trouble receiving email from a specific domain (they are hosted by Cisco IronPort). They are not on a blacklist and neither are
we.
We have most settings on default or recommended. All other email from the Internet we have no problem receiving. We have SPF and DNS reverse lookup setup correctly on our domain.
I am working with the other company to try and resolve this. We have both contacted our ISPs and they have reported back that they are not blocking any SMTP traffic from either IP range.
DNS reverse lookup seems fine on mxtoolbox. Here is our info:
Domain = vsbdc.com
IP = 68.65.66.82
MX = mail.vsbdc.com
PTR = 68.65.66.82 mail.vsbdc.com
SPF record checks out too