How do Apple Mail user settings impact email deliverability and spam filtering?

Key findings

• Client-side impact: Apple Mail user settings primarily affect spam filtering within the individual's local mail client, not the overarching spam filters of mailbox providers like iCloud or Gmail.
• Limited global influence: While manual actions (such as adding an email to contacts or marking it not junk) can improve delivery for that specific user, their collective impact on a sender's overall deliverability across all Apple users or other mailbox providers is generally minimal.
• Privacy features: Features like Mail Privacy Protection (MPP) and Private Relay aim to enhance user privacy, obscuring data like open rates and IP addresses, which requires marketers to adapt their measurement and targeting strategies.
• Authentication remains key: Despite client-side settings, adherence to email authentication standards such as SPF, DKIM, and DMARC remains foundational for overall deliverability, including to iCloud Mail.

Key considerations

• User adoption rates: The effectiveness of asking users to add senders to contacts or mark emails as not junk is limited by how many users actually follow these steps, which is typically low.
• Focus on sender reputation: To improve deliverability to Apple users, focus on fundamental practices that build a strong sender reputation, such as sending relevant content, maintaining a clean list, and avoiding spam traps.
• Client vs. provider filtering: Distinguish between client-side spam settings (e.g., in Apple Mail app) and server-side filtering by mailbox providers (e.g., iCloud, Gmail), as they operate independently.
• Adapt to privacy changes: Adjust email strategies to account for Apple's privacy features, recognizing their impact on traditional metrics like open rates and focusing on alternative engagement signals. For more, see Demand Gen Report's insights.

Key opinions

• Standard but hard to measure: Many marketers acknowledge that advising users to add senders to contacts is standard practice, but its actual effectiveness and the rate of user compliance are difficult to quantify.
• Low user adoption: There's skepticism that a significant number of users will actively complete these manual steps, thereby limiting their overall impact on deliverability.
• Historical advice: The advice to whitelist emails has historical roots (dating back to AOL days), but its relevance and impact on modern mail servers and spam filters are debated.
• Client-specific impact: Any positive impact from user settings is generally confined to the individual Apple Mail client and does not extend to the broader filtering decisions of major mailbox providers.
• Privacy challenges: Apple's privacy features, particularly Mail Privacy Protection, have significantly impacted open rate tracking, forcing marketers to rethink engagement metrics.

Key considerations

• Don't expect miracles: While harmless to suggest, marketers should not rely on user-initiated actions as a primary strategy for improving overall email deliverability or solving widespread spam placement issues.
• Focus on core deliverability: Prioritize fundamental deliverability best practices, such as maintaining a healthy sending reputation and segmenting engaged audiences, which have a much larger impact. For instance, understanding why your emails are going to spam is more critical.
• Adapt tracking methods: With Apple's privacy changes, marketers need to adapt their campaign tracking beyond traditional open rates, focusing on clicks, conversions, and other direct engagement metrics.
• Educate clients (if applicable): Inform clients or internal teams that inbox placement tests can be influenced by client-side settings, but true deliverability is a function of broader sender reputation and authentication.

Key opinions

• Client vs. provider filtering: User settings in the Apple Mail client only affect its local spam filter; they do not influence the broader spam filtering mechanisms of providers like iCloud or Gmail.
• Overestimated impact: The direct influence of manual whitelisting or marking as 'not spam' on global deliverability to Apple's iCloud is often exaggerated compared to larger sender reputation factors.
• Privacy, not deliverability: Apple Mail Privacy Protection primarily aims to enhance user privacy and does not alter core email authentication standards such as SPF, DKIM, or DMARC.
• Reputation is paramount: Apple's approach to email filtering for iCloud heavily relies on sender reputation, which is built through consistent good sending practices, rather than granular user-initiated actions.
• Focus on fundamentals: Email deliverability challenges with Apple recipients often originate from issues with sender reputation and email authentication, not client-side settings. Ensure your DMARC, SPF, and DKIM are properly configured.

Key considerations

• Prioritize core deliverability: Instead of focusing on client-side settings, senders should invest in maintaining a strong sender reputation, including low complaint rates, low bounce rates, and high engagement metrics across their subscriber base.
• Understand privacy impacts: Recognize that Apple's privacy features will impact the data you collect, making traditional open rates unreliable. Shift your focus to other engagement signals like clicks and conversions.
• Implement strong authentication: Ensure proper implementation of SPF, DKIM, and DMARC. These authentication methods are critical for proving your legitimacy to mailbox providers and avoiding DMARC verification failures.
• Monitor performance comprehensively: Use various tools and metrics to monitor deliverability beyond simple inbox placement tests, including bounce rates, complaint rates, and overall engagement trends.

Key findings

• Authentication standards: Apple's postmaster information for iCloud Mail heavily stresses the requirement for senders to implement and adhere to email authentication standards such as SPF and DKIM.
• Bulk sending guidelines: Documentation provides specific guidelines for bulk email senders, emphasizing responsible practices to prevent delivery issues and maintain a positive sending reputation.
• Client-side vs. server-side: While client-side settings exist (e.g., allow mail from contacts), the primary filtering decisions for iCloud Mail are made at the server level, based on sender reputation and compliance.
• Privacy features' scope: Updates like iOS 18 and Mail Privacy Protection introduce features related to how emails are displayed and user privacy, but they do not fundamentally alter core email deliverability rules at the server level.
• Reputation as a key factor: Low IP or domain reputation is consistently cited as a common reason for emails being filtered to spam, underlining the importance of maintaining good sender health.

Key considerations

• Adhere to postmaster guidelines: For senders to iCloud Mail, review and comply with Apple's postmaster information, particularly regarding authentication and bulk sending practices.
• Prioritize sender reputation: Focus on practices that build and maintain a strong sender reputation, such as sending valuable content, managing subscriber engagement, and avoiding spam complaints, as highlighted by various email service providers.
• Understand privacy features: Familiarize yourself with features like Apple's Private Relay Service and how they impact data rather than core deliverability logic, as indicated by documentation like Bloomreach's iOS 18 update analysis.
• Maintain list hygiene: Regularly clean your email lists and ensure you're only sending to engaged recipients. This practice directly affects your list health and, consequently, your sender reputation and deliverability.
• Content quality: Ensure your email content is high quality and relevant to your audience to minimize spam complaints, which heavily influence spam filtering.