Problem with moving email servers to new IP

imageWe have discovered a rather annoying email problem this week. Because of a closure of a data centre we have used for over 10 years, we have been forced to pickup our servers and move them over to a new data centre. As annoying and as much work as this is, we have found one particular issue with the change of our primary email servers over to a new IP.

In recent years, there has been a new emergence of spam email fighting systems. Cisco is using it’s power of basically routing almost every bit of data on the internet to directly monitor IP addresses real time. They call this and is part of their IronPort spam scanning service.

We have had our email servers running for years with a “Good” reputation on this service.


However when we move the IP to a new block, we have found that almost instantly, the IronPort services rank us as “poor” due to the fact that they monitor days / weeks / months of average email sent from the address. When we instantly move to a new address that last month did no email, and start blasting email galore through one IP. Bang we are canned.

In the past this has not been a big issue. But in Australia, our primary telco has recently been pushing an email spam service that relies heavily on this service. So we are finding that loads of Australian businesses are blocking our email services. The solution has been to relay through some other email services, but that is time consuming and fiddly, as we still have to leave the majority of email running through the new IP so that it develops a “good” reputation on the IronPort services.

Wouldn’t it be nice if the support people at IronPort answered emails for support to move the reputation of an old IP address over to a news one!

– Update- Since we wrote this. We have been in contact with the senderbase support people who have ranked us a “Good”. It took 3 email messages and 7 days, but they did finally assist.

As it turns out, this ranking is one of the most important aspects of running a valid email server. It is a shame they do not have a more transparent method of making the requests for review. We still cannot work out exactly what the cause of the poor ranking was. There is the possibility that it way by association with the network owner who would appear to deserve a ranking of poor.

How to turn off NDR’s in Exchange 2003

Understanding non-delivery reports

NDR or Non Delivery Reports are potentially a great way of telling a user that they made a typo with an email address and that the email could not be delivered. In a 1999 world, this would be fine.

However we are in a world now where email servers are flooded with spam, and lots of it, replying to every junk email that is hitting all the imaginary email addresses on your server (support@, admin@ help@ etc) is not a good idea, and it causes what is known as backscatter. To avoid this back scatter of invalid email delivery from your server it is recommended that you turn off your Non Delivery Reports NDR.

To do this in Exchange 2003 you need to perform the folloing:

1. Open Exchange System Manager

2. Expand Global Setting and Click on Internet Message Formats


3. In the right hand pane, double click the “Default” name or whatever domain you have configured.

4. Click on the Advanced Tab and uncheck the option for Allow non-delivery reports


5. Ok and you are done!

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