Exchange 2010 getting blacklisted all the time

[nathan3388]

we have an email server that is getting blacklisted all the time. I have checked the logs and it aint sending any spam out, nor can someone use an open relay was wondering what over steps or diagnostics I could use to determine where the problem lies. this is what the company has sent me to check which I have and all come back clear.

 

Thank you for contacting Barracuda Networks regarding your issue. Your issue is important to us. We have assigned a confirmation number: to this case.

 

We apologize for any inconvenience that this may have caused you. We have removed (Please wait 24-48 hours) from our blocklist for 30 days, at which time it will be re-evaluated.

 

There are a number of reasons your IP address may have been listed as "poor", including:

 

The email server at this IP address contains a virus and has been sending out spam

The email server at this IP address may be configured incorrectly

The PC at this IP address may be infected with a virus or botnet software program

An individual in the organization at this IP address may have a PC infected with a virus or botnet program

This IP address may be a dynamic IP address which was previously utilized by a known spammer

The marketing department of a company at this IP address may be sending out bulk emails that do not comply with the CAN-SPAM Act

This IP address may have a insecure wireless network attached to it which could allow unknown users to use it's network connection to send out bulk email

In some rare cases, your recipients' Barracuda Spam Firewall may be misconfigured

If you do not think any of the above apply, please also contact the person who manages this IP address, as they may be better able to investigate this issue.

 

Thank you for your time and understanding.

 

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BarracudaCentral.org - Technical Insight for Security Pros

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[NokiX]

I'd recommend sending a test message over to https://www.mail-tester.com/ as that will flag up any issues that may be causing blacklisting such as an issue with RDNS or other DNS related problems. If you don't get any problems reported on mail-tester you need to try and get barracuda to provide some evidence of what they are recording that warrants a poor rating, they should be able to provide this to you in some form or another so you can at least debug the problem further.

 

While I have plenty of experience with Exim/Dovecot setups, it's been a while since I've dealt with exchange so I can't think of anything off the top of my head but hopefully the above helps!