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Help with Email MX Records, etc

Last Modified: 2017-08-30
Hi all.
We are running Exchange 2007 with a Barracuda Spam filter.
Optimum is our ISP.
We are unable to send email to a specific domain.
We get an NDR (eventually) stating:
"#< #4.0.0 X-Spam-&-Virus-Firewall; connect to mx00.1and1.com[]: server refused mail service> #SMTP#"

When I run an SMTP test on our domain name in MXToolbox.com we get the following warnings:
MXToolbox Results
Is there anyone here that can help me try and resolve these issues?  I'm guessing if we clear all 3 we will be able to send email to that domain.
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