Why am I seeing "Your network settings prevent content from loading privately" in the mail apps after updating Pi-hole?

After a recent update to my Pi-hole server, I'm now seeing the warning "Your network settings prevent content from loading privately" above email messages in the Mail apps in iOS/iPadOS 15.x and macOS v12 (Monterey) when I'm connected to my home Wi-Fi, preventing me from using the "Protect Mail Activity" feature in iOS 15.


Recent versions of Pi-hole automatically sink hole requests to two key Apple domains (mask.icloud.com and mask-h2.icloud.com) to prevent the Apple Private Relay feature from bypassing Pi-hole. Due to this, the "Protect Mail Activity" feature in iOS 15 may not work when connected to a network using a Pi-hole server.

In iOS, the "Protect Mail Activity" feature is found under SettingsMailPrivacy Protection. In macOS, it's found under MailPreferencesPrivacy.

To resolve this, add the BLOCK_ICLOUD_PR=false setting to your Pi-hole server's pihole-FTL.conf file using the following steps:

  1. SSH to your Pi-hole server
  2. Run the following command: sudo nano /etc/pihole/pihole-FTL.conf
  3. Append the following setting to this file and save the file: BLOCK_ICLOUD_PR=false
  4. Either restart your Pi-hole server, or just restart the DNS Resolver service with pihole restartdns

Pi-hole documentation: BLOCK_ICLOUD_PR=true|false (PR #1171)