Allowlisting - Automatically Download Images For Emails Sent To Microsoft 365

Would you like to have images automatically download for simulated phishing and notification emails sent by GrintOps?

In this support article we'll walk through the allowlisting process to add GrintOpsmanaged domains to the Outlook Safelist Collection, ensuring images are automatically downloaded. This has the added benefit of ensuring the email view metric in simulated phishing campaigns is accurate. However, the email view metric isn't essential to the success of campaigns, and as a result, this guidance is purely optional and can be added at your own discretion.

Note: The guidance in this article builds upon Microsoft guidance on configuring the safelist collection on an Microsoft 365 mailbox. Please refer to this article to learn more about mailbox safelist collections.

Table Of Contents:

Prerequisites

Step 1: Connect to Exchange Online PowerShell

Open PowerShell with administrative privileges and connect to Exchange Online:

Import-Module ExchangeOnlineManagement
Connect-ExchangeOnline -UserPrincipalName your_admin_account@yourdomain.com

Note: Replace your_admin_account@yourdomain.com with your admin username.

Step 2: Define the Domains to Add

Create an array containing the GrintOps domains you wish to add to the Safe Senders list:

$domains = @(
    'office365-webnotif.com',
    'office365-webnotif.site',
    'miro-apps.online',
    'ukum0nline.com',
    'slack-apps.online',
    'github-apps.online'
)

Note: If you've setup white-labelling, we recommend adding your white-labelled domain to the list.

Step 3: Add Domains to All Mailboxes

Run the following command to add the specified domains to the Safe Senders list for all users:

The following is an example of how to add domains to the Safe Senders list for all mailboxes:

# Fetch all mailboxes once
$mailboxes = Get-Mailbox -RecipientTypeDetails UserMailbox -ResultSize Unlimited

# Add each domain one at a time for every mailbox
foreach ($domain in $domains) {
  foreach ($mbx in $mailboxes) {
      Set-MailboxJunkEmailConfiguration `
          -Identity $mbx.Identity `
          -TrustedSendersAndDomains @{ Add = $domain }
  }
  # Pause for 1 second before moving to the next domain
  Write-Host "Added '$domain' to TrustedSendersAndDomains for all mailboxes."
  Start-Sleep -Seconds 1
}

Explanation:

Step 4: Verify the Changes

To confirm that the domains have been added, you can check the Safe Senders list of a specific mailbox:

Get-MailboxJunkEmailConfiguration -Identity user@domain.com | Select-Object -ExpandProperty TrustedSendersAndDomains

Note: Replace user@domain.com with the email address of a user in your organization.

Additional Notes