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Redundancy - MX records and second server

    Question

  • Hello

    Could you please advise me, what is the best practice regarding the redundancy for exchange server. We have now one exchange server running and one mx record set, pointing to this server.

    What I would like to achieve, is that if our server failed, second mx record, that would be pointed to a different server would still be working.

    thank you in advance for your suggestions.

    Jakub

    Saturday, March 10, 2012 8:00 PM

Answers

  • I hope this helps

    You can install more than one Edge Transport server in the perimeter network. Deploying more than one Edge Transport server provides redundancy and failover capabilities for your inbound message flow. You can load-balance SMTP traffic to your organization between Edge Transport servers by defining more than one mail exchange (MX) resource record with the same priority in the Domain Name System (DNS) database for your mail domain. You can achieve consistency in configuration between multiple Edge Transport servers by using cloned configuration scripts.

    http://technet.microsoft.com/en-us/library/bb124701.aspx 
    http://technet.microsoft.com/en-us/library/dd638137.aspx#HA

    Gulab Prasad,
    MCITP: Exchange Server 2010 | MCITP: Exchange Server 2007
    MCITP: Lync Server 2010 | MCITP: Windows Server 2008
    My Blog | Z-Hire Employee Provisioning App

    • Marked as answer by Jakub_S Sunday, March 11, 2012 2:48 PM
    Sunday, March 11, 2012 5:38 AM
  • Do you have another Exchange server?

    If not, then what are you going to do with the email? There are backup MX record services which will simply queue the email for you, or you could build you own using a Windows 2003 machine and the standard IIS SMTP engine. Whatever you do, ensure that the second MX record has the same level of antispam and AV protection as your primary as spammers actively target so called "secondary" MX records. You should ensure that whatever you use can do LDAP lookups for recipient filtering, so that your second host doesn't cause back scatter.

    Also do not be fooled in to thinking that the secondary MX record will not be used, as it will. As far as I am concerned, the "cost" on MX records is meaningless and therefore all MX records should be treated as production.

    Do not be tempted to simply use another mail server with accounts in place as that will mean getting the email in to your production system will be troublesome.

    The easiest method though is to simply have two Exchange servers. If Exchange 2010 have them in a DAG and then replicate the data. Email can be delivered to any Exchange server in the org and if the one the server wants to deliver to isn't available, the email will simply queue, but is at least under your control.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.

    • Marked as answer by Jakub_S Sunday, March 11, 2012 2:49 PM
    Sunday, March 11, 2012 12:10 PM

All replies

  • I hope this helps

    You can install more than one Edge Transport server in the perimeter network. Deploying more than one Edge Transport server provides redundancy and failover capabilities for your inbound message flow. You can load-balance SMTP traffic to your organization between Edge Transport servers by defining more than one mail exchange (MX) resource record with the same priority in the Domain Name System (DNS) database for your mail domain. You can achieve consistency in configuration between multiple Edge Transport servers by using cloned configuration scripts.

    http://technet.microsoft.com/en-us/library/bb124701.aspx 
    http://technet.microsoft.com/en-us/library/dd638137.aspx#HA

    Gulab Prasad,
    MCITP: Exchange Server 2010 | MCITP: Exchange Server 2007
    MCITP: Lync Server 2010 | MCITP: Windows Server 2008
    My Blog | Z-Hire Employee Provisioning App

    • Marked as answer by Jakub_S Sunday, March 11, 2012 2:48 PM
    Sunday, March 11, 2012 5:38 AM
  • Do you have another Exchange server?

    If not, then what are you going to do with the email? There are backup MX record services which will simply queue the email for you, or you could build you own using a Windows 2003 machine and the standard IIS SMTP engine. Whatever you do, ensure that the second MX record has the same level of antispam and AV protection as your primary as spammers actively target so called "secondary" MX records. You should ensure that whatever you use can do LDAP lookups for recipient filtering, so that your second host doesn't cause back scatter.

    Also do not be fooled in to thinking that the secondary MX record will not be used, as it will. As far as I am concerned, the "cost" on MX records is meaningless and therefore all MX records should be treated as production.

    Do not be tempted to simply use another mail server with accounts in place as that will mean getting the email in to your production system will be troublesome.

    The easiest method though is to simply have two Exchange servers. If Exchange 2010 have them in a DAG and then replicate the data. Email can be delivered to any Exchange server in the org and if the one the server wants to deliver to isn't available, the email will simply queue, but is at least under your control.

    Simon.


    Simon Butler, Exchange MVP
    Blog | Exchange Resources | In the UK? Hire Me.

    • Marked as answer by Jakub_S Sunday, March 11, 2012 2:49 PM
    Sunday, March 11, 2012 12:10 PM