Connect Application: Adding Permitted Senders

Document created by user.oxriBaJeN4 Employee on Oct 22, 2015Last modified by user.m8lcBwVNwY on May 16, 2017
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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.




To protect you from spam, we apply strict screening to all inbound emails from unknown external senders. When you first connect to us, we do not know who you regularly communicate with. Therefore we treat all external senders as unknown, which can slow down your inbound email processing. As we handle your outbound email, we will observe who you communicate with and mark them as permitted senders.


You can let us know in advance who you regularly communicate with. This enables us to mark these additional addresses as permitted senders, thereby ensuring email from them bypasses our strict spam scanning. To help you, we've provided a application that you can download and run over a period of days. It gathers details of external email addresses you regularly communicate with, outputting them to a CSV file. When you are ready, you can import the CSV file to add these users to your managed senders list.


What You'll Need


  • .NET Framework version 4 installed on a Windows PC or server.
  • The Contacts Export Wizard application (see below).
  • An account with Application Impersonation.
  • For an On-Premises Exchange installation, a publicly published EWS endpoint (Exchange 2007 SP1 and later).


Adding Permitted Senders


To compile and add a list of permitted senders:

  1. Add Permitted SendersClick the Gateway | Add Permitted Users menu item. The page displays the current state of your permitted senders including:
    • Users added to date
    • The time your outbound email was setup.
  2. Click the Start button.
  3. Click the Download button. The application's .EXE file is downloaded to your browser's download location.
  4. Run the application. It runs in the background gathering details of who you communicate with.
  5. Stop the application. The .CSV file is saved to your browser's download location.
    You can manually add email addresses or domains to the CSV file using the format "<internal user address>, <external address or domain>, PERMIT". For example:
    ,, PERMIT
    ,, PERMIT
  6. Click the Select CSV File button to open a file browser.
  7. Select the .CSV file output by the application. The file is automatically validated and, if successful, imported.
    Steps 6 and 7 can be performed in one step by clicking and dragging the .CSV file into the file field.

Once the permitted senders status is updated, a summary is displayed of the number of permitted senders added.

The total number of rows per upload is 50,000. Perform multiple uploads should you need to add more this limit.

See Also...