feat: add SKIP_INCOMING_BCC_PROCESSING as internal config (#12484)

Co-authored-by: Muhsin Keloth <muhsinkeramam@gmail.com>

app/finders/email_channel_finder.rb

@@ -6,19 +6,54 @@ class EmailChannelFinder
   end
 
   def perform
-    channel = nil
-
-    recipient_mails.each do |email|
-      normalized_email = normalize_email_with_plus_addressing(email)
-      channel = Channel::Email.find_by('lower(email) = ? OR lower(forward_to_email) = ?', normalized_email, normalized_email)
-
-      break if channel.present?
-    end
-    channel
+    channel_from_primary_recipients || channel_from_bcc_recipients
   end
 
-  def recipient_mails
-    recipient_addresses = @email_object.to.to_a + @email_object.cc.to_a + @email_object.bcc.to_a + [@email_object['X-Original-To'].try(:value)]
-    recipient_addresses.flatten.compact
+  private
+
+  def channel_from_primary_recipients
+    primary_recipient_emails.each do |email|
+      channel = channel_from_email(email)
+      return channel if channel.present?
+    end
+
+    nil
+  end
+
+  def channel_from_bcc_recipients
+    bcc_recipient_emails.each do |email|
+      channel = channel_from_email(email)
+
+      # Skip if BCC processing is disabled for this account
+      next if channel && !allow_bcc_processing?(channel.account_id)
+
+      return channel if channel.present?
+    end
+
+    nil
+  end
+
+  def primary_recipient_emails
+    (@email_object.to.to_a + @email_object.cc.to_a + [@email_object['X-Original-To'].try(:value)]).flatten.compact
+  end
+
+  def bcc_recipient_emails
+    @email_object.bcc.to_a.flatten.compact
+  end
+
+  def channel_from_email(email)
+    normalized_email = normalize_email_with_plus_addressing(email)
+    Channel::Email.find_by('lower(email) = ? OR lower(forward_to_email) = ?', normalized_email, normalized_email)
+  end
+
+  def bcc_processing_skipped_accounts
+    config_value = GlobalConfigService.load('SKIP_INCOMING_BCC_PROCESSING', '')
+    return [] if config_value.blank?
+
+    config_value.split(',').map(&:to_i)
+  end
+
+  def allow_bcc_processing?(account_id)
+    bcc_processing_skipped_accounts.exclude?(account_id)
   end
 end