I’m writing with absolute conviction when I say that this is one deliverable I’m sure a lot of customers with hosted domains will be very happy about! Particularly those managing their own DNS records or those running their own mail servers.

Today we will be looking to provide functionality on the portal that will allow customers to remove the mx.last secondary mail record from domains they have hosted on their account.

This is something that we often receive requests for, especially from business users. It’s also the 5th most voted for network feature over on the Usergroup Issue tracker.

Removing the mx.last MX record from a domain allows customers with the necessary technical expertise to manage their own email in it’s entirety without being forced to use our back-up mail servers.

When an e-mail message is sent through the Internet, the sending mail transfer agent makes a DNS query requesting the MX records of the recipient’s email address. It’s these records that tell the sender where abouts on the Internet to attempt to deliver the email. A PlusNet domain commonly has two of these records:-

nothingheretosee.co.uk. MX 10 mx.core.plus.net.
nothingheretosee.co.uk. MX 20 mx.last.plus.net.

mx.core.plus.net routes to our primary mail delivery servers whilst mx.last.plus.net routes to our secondary mail delivery servers. The MX record with the smallest preference number has the highest priority and is the first server to be tried. When an email is sent to a PlusNet address, delivery will initially be attempted to mx.core.plus.net. In the unlikely event that these servers are unavailable or offline, mail will instead be delivered to mx.last.plus.net. The idea is to have back-up servers should the primary ones fail.

When a customer switches to using SMTP mail delivery or elects to manage their domain records themselves, the back-up record is left intact, so you end up with something like this:-

nothingheretosee.co.uk. MX 5 mail.nothingheretosee.co.uk.
nothingheretosee.co.uk. MX 10 autoturn.plus.net.
nothingheretosee.co.uk. MX 20 mx.last.plus.net.

This has been known to cause frustration in the past because until now customers have been unable to remove the mx.last record, even when choosing the option to manage their email themselves via the portal. There are several reasons somebody might want to do this. Some customers do not want to rely on a third party (ie. us) to handle their email, whilst with others the presence of the back-up record has the potential to interfere with their local spam detection rules.

Spammers will often target the MX record with the highest preference number. They do this because secondary/back-up mail servers are known to be less protected against spam when compared to a provider’s primary servers.

In reality mx.core.plus.net is rarely unavailable which somewhat negates the requirement for the back-up servers. Legitimate email will sometimes reach mx.last.plus.net but examples of this are seldom encountered. Basically, almost all of the email sent via mx.last is spam!

Customers can configure their domain records via the Member Centre by navigating to:

Member Centre > Domain Names > Configure > Configure DNS Records

• Read more about MX records
• Read the domain records Usertools tutorial
• Read the Domain Administration help pages

Bob

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This entry was posted by Bob Pullen on Monday, July 30th, 2007 at 2:09 pm and is tagged with Email and is posted in the category PlusNet News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.