Setting Up an Internal Newsletter
Without Extra Licences

// Trigger: When new Forms response submitted (Unsubscribe form)
// Action 1: Get items from Subscribers list
Filter Query: Email eq '@{triggerOutputs()?['body/responderEmail']}'

// Action 2: Apply to each result
  Update item:
    Status        → "Inactive"
    UnsubscribedOn → utcNow()

// Action 3: Send goodbye email
  To:      responder email
  Subject: "You have been unsubscribed"
  Body:    confirmation + re-subscribe link

// Compose action — "htmlBase" variable
replace(
  replace(
    replace(
      replace(
        outputs('Get_template_item')?['fields']?['TemplateHtml'],
        '{{NEWSLETTER_TITLE}}', triggerBody()?['text_TITLE']
      ),
      '{{SUBTITLE}}', triggerBody()?['text_SUBTITLE']
    ),
    '{{INTRO_TEXT}}', triggerBody()?['text_INTRO']
  ),
  '{{SP_PAGE_LINK}}', triggerBody()?['text_SP_LINK']
)
// Chain as many replace() as you have variables

replace(
  replace(
    variables('htmlBase'),
    '{{RECIPIENT_FIRSTNAME}}',
    items('Apply_to_each')?['FirstName']
  ),
  '{{UNSUBSCRIBE_LINK}}',
  concat(
    'https://company.sharepoint.com/sites/Communication/SitePages/unsubscribe.aspx?email=',
    encodeUriComponent(items('Apply_to_each')?['Email'])
  )
)

# Connect to Exchange Online
Connect-ExchangeOnline

# Check current state across all policies
Get-OwaMailboxPolicy | Select Name, OutlookNewslettersAccessLevel

# Enable for the whole tenant (ReadWrite = create + read)
Set-OwaMailboxPolicy -Identity "OwaMailboxPolicy-Default" `
  -OutlookNewslettersAccessLevel ReadWrite `
  -OutlookNewslettersReactions   DefaultOn `
  -OutlookNewslettersShowMore     DefaultOn

# --- RESTRICT to a pilot group only ---
# Set default to ReadOnly (everyone can read, not create)
Set-OwaMailboxPolicy -Identity "OwaMailboxPolicy-Default" `
  -OutlookNewslettersAccessLevel ReadOnly

# Create a dedicated policy for the Communication team
New-OwaMailboxPolicy -Name "OwaPolicy-NewsletterAuthors"
Set-OwaMailboxPolicy -Identity "OwaPolicy-NewsletterAuthors" `
  -OutlookNewslettersAccessLevel ReadWrite

# Assign policy to specific users
Set-CASMailbox -Identity "alice@company.com" `
  -OwaMailboxPolicy "OwaPolicy-NewsletterAuthors"

# Or assign to all members of a group (no direct group assignment in EAC)
Get-DistributionGroupMember -Identity "NL-Newsletter-Authors" | ForEach-Object {
  Set-CASMailbox -Identity $_.PrimarySmtpAddress `
    -OwaMailboxPolicy "OwaPolicy-NewsletterAuthors"
}

<hr style="border:none;border-top:1px solid #e0e0e0;margin:12px 0;">
<table cellpadding="0" cellspacing="0" border="0">
  <tr>
    <td style="padding-right:10px;font-family:Arial,sans-serif;
            font-size:12px;color:#666;vertical-align:middle;">
      📩 Internal newsletter
    </td>
    <td style="vertical-align:middle;">
      <a href="YOUR_SUBSCRIPTION_LINK"
         style="display:inline-block;background:#0078d4;color:#ffffff;
                font-size:11px;font-weight:bold;padding:4px 10px;
                border-radius:12px;text-decoration:none;">
        Subscribe →
      </a>
    </td>
  </tr>
  <tr>
    <td colspan="2"
        style="font-family:Arial,sans-serif;font-size:11px;
               color:#999;padding-top:3px;">
      M365 &amp; SharePoint updates &amp;middot; Monthly
    </td>
  </tr>
</table>

<hr style="border:none;border-top:1px solid #e0e0e0;margin:12px 0;">
<p style="font-family:Arial,sans-serif;font-size:12px;color:#555;margin:0;">
  📬 <a href="YOUR_SUBSCRIPTION_LINK"
        style="color:#0078d4;text-decoration:none;font-weight:bold;">
    Subscribe to our monthly internal newsletter
  </a>
  <span style="color:#bbb;"> · M365 &amp; SharePoint</span>
</p>

Connect-ExchangeOnline

# HTML block to append (store in variable)
$signatureHtml = @"
<hr style='border:none;border-top:1px solid #e0e0e0;margin:12px 0;'>
<table cellpadding='0' cellspacing='0' border='0'>
  <tr>
    <td style='padding-right:10px;font-family:Arial,sans-serif;
               font-size:12px;color:#666;vertical-align:middle;'>
      📩 Internal newsletter
    </td>
    <td style='vertical-align:middle;'>
      <a href='YOUR_SUBSCRIPTION_LINK'
         style='display:inline-block;background:#0078d4;color:#ffffff;
                font-size:11px;font-weight:bold;padding:4px 10px;
                border-radius:12px;text-decoration:none;'>
        Subscribe →
      </a>
    </td>
  </tr>
  <tr>
    <td colspan='2'
        style='font-family:Arial,sans-serif;font-size:11px;
               color:#999;padding-top:3px;'>
      M365 & SharePoint updates · Monthly
    </td>
  </tr>
</table>
"@

# Create the transport rule scoped to a group
New-TransportRule `
  -Name                          "SIG – Newsletter promo – Communication" `
  -FromMemberOf                  "NL-Newsletter-Senders" `
  -ApplyHtmlDisclaimerLocation   Append `
  -ApplyHtmlDisclaimerText       $signatureHtml `
  -ApplyHtmlDisclaimerFallbackAction Wrap `
  -ExceptIfFrom                  "newsletter@company.com" `
  -Enabled                       $true

# Update the HTML later (e.g. new subscription link) without recreating the rule
Set-TransportRule `
  -Identity                    "SIG – Newsletter promo – Communication" `
  -ApplyHtmlDisclaimerText     $signatureHtml_updated

// Auto-include all users in the "Communication" department
(user.department -eq "Communication") or
(user.jobTitle -contains "Director")