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akashg88's avatar
akashg88
Copper Contributor
May 02, 2019

Hybrid mail flow with IronPort

Hi,

One of my customer has the following setup, and I'd need some recommendation to setup a hybrid mail flow -

 

Incoming emails -

Internet -> Cisco ASA firewall -> on premise Ironport -> Exchange servers.

Outgoing emails -

Exchange servers -> Ironport -> Cisco ASA firewall -> Internet.

 

We want to setup hybrid, and figure out a way to bypass Ironport as Microsoft recommends that there should not be any device between secure mail flow between online and on premise exchange servers. Any ideas on how to setup hybrid mail flow bypassing Ironport ?

exchange
hybrid
migration
office 365

4 Replies

  • HarishSolanki's avatar
    HarishSolanki
    Copper Contributor
    Jan 15, 2021

    Hi akashg88,

    I have a similar setup and planning to implement Exchange in Hybrid mode. 

    Please share your solution to me. 

    Thanks!

     

     

  • NunoAriasSilva's avatar
    NunoAriasSilva
    MVP
    May 02, 2019

    Hi akashg88 

     

    Is not advised by Microsoft to have any device between Exchange and Office 365, but you can setup hybrid and change de Connectors, both on-premises and Online to point to your infrastructure, but for best security you must enable TLS on those devices and Exchange Online and OnPremises Connectors.

    • akashg88's avatar
      akashg88
      Copper Contributor
      May 02, 2019

      Hi NunoAriasSilva 

      Thanks for your response - I agree that there shouldn't be any device and I am trying to figure out a way to bypass Ironport, but unable to do so. 

       

      Is there a way by which I can bypass Ironport considering that traffic on firewall for port 25 is NATed to go to Ironport first. How do I bifurcate the traffic ?

      NunoAriasSilva wrote:

      Hi akashg88 

       

      Is not advised by Microsoft to have any device between Exchange and Office 365, but you can setup hybrid and change de Connectors, both on-premises and Online to point to your infrastructure, but for best security you must enable TLS on those devices and Exchange Online and OnPremises Connectors.

       

      • Spiros Karampinis's avatar
        Spiros Karampinis
        Brass Contributor
        Jan 15, 2020

        akashg88 please have a look at the following post from Cisco

         

        https://www.cisco.com/c/en/us/support/docs/security/cloud-email-security/214812-configuring-office-365-microsoft-with.html

         

        Could that help you solve your issue ?

         

        Kind regards

        Spiros

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