Connect Application: Preparing for Inbound Email

Document created by user.oxriBaJeN4 Employee on Oct 22, 2015Last modified by user.Yo2IBgvWqr on Feb 7, 2018
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Applies To



  • New clients connecting with Mimecast using the Connect Application. If you are not using the Connect Application, click here.
  • Customers who are using Mimecast for email security.




You'll need to prepare your Exchange to accept inbound emails that have been routed through us. Before preparing your inbound email, the following steps must be completed:


To prepare your inbound email:

  1. Click on the Gateway | Prepare for Inbound Email menu item.
  2. Click the Start button.
  3. Configure your Exchange to accept inbound emails through us. The process for doing this depends on the Exchange type:

Before inbound email can be routed through us, you must also modify your MX records. This step designates us as the mail service responsible for accepting email on your behalf. Read the Modifying Your MX Records page for further details.

Office 365


To prepare Office 365 to accept inbound mail that has been routed through us:

  1. Configure Office 365 to accept inbound email from us, by setting the IP addresses displayed in the application as a trusted source.
    See the Bypassing Spam Checks section of the inbound delivery routing page for further details.
  2. Determine your Office 365 inbound mail flow hostname:
    1. Log in to the Office 365 Admin Center.
    2. Click on the Manage | Domains menu item on the left hand side.
    3. Select your Domain.
    4. Click on the Domain Settings link on the right hand side. The DNS Management dialog is displayed.
    5. Make a note of the hostname displayed.
  3. Click the Next button to proceed.
  4. Enter your Office 365 inbound mail flow hostname in the Hostname field.
  5. Click the Verify Route button. The Test Inbound Host dialog is displayed.
  6. Test Inbound HostEnter a valid Internal Email Address so we can verify your inbound route.
  7. Click on the Test button.
  8. Click the Finish button. A summary page of your inbound email connection is displayed.

If you’ve created an "Everyone To Internal " delivery route policy using the Administration Console, an option is presented to use it rather than create a new one.

On Premise / Hybrid / Hosted Exchange


To prepare your Exchange to accept inbound email that has been routed through us, read the Preparing for Inbound Email page.