How to address deliverability issues with acquired email list in Mailchimp, specifically high abuse complaints from Microsoft, Yahoo, and Comcast?

Key findings

• Selective complaints: High abuse complaints primarily from Microsoft, Yahoo, and Comcast suggest that these ISPs have more stringent filtering or better feedback loops (FBLs) compared to others like Gmail, which may not report complaints in the same traditional manner.
• FBLs are manual: Mailchimp and similar platforms typically report abuse complaints that originate from subscribers manually marking emails as spam, which are fed back via FBLs.
• Thresholds are low: A complaint rate exceeding 0.1% is generally considered elevated and can severely impact deliverability. Even rates around 0.05% or 0.07% are concerning.
• Expectation mismatch: When subscribers of an acquired company are emailed by a new entity (even if branding remains similar), there can be an expectation mismatch leading to increased complaints.
• List age and consent: Lack of information on how the acquired list performed previously or whether consent was re-established can indicate underlying issues. Acquired lists often present deliverability challenges, as detailed in our guide on why purchased email lists cause deliverability issues.

Key considerations

• Understand complaint sources: While Mailchimp classifies abuse complaints as manual, certain ISPs (like Microsoft or Yahoo) might incorporate filtering signals or user behavior (like auto-deleting spam) into their complaint reporting mechanisms, affecting their calculation of email complaint rates.
• Re-engagement strategy: Consider a permission pass or a series of re-engagement messages to the acquired list. This helps identify active subscribers and allows for permanent suppression of uninterested contacts.
• List segmentation: Segment your list based on engagement to identify active versus inactive subscribers. Focusing on engaged users can help improve overall sender reputation.
• Review bounce reasons: Go beyond simple soft bounce classification. Analyze specific bounce reasons (e.g., full mailbox, no MX record) to determine whether to re-attempt delivery or permanently remove the address. This is a key part of email deliverability best practices.
• Proactive management: Actively manage your list and unsubscribe rates, even if complaint rates appear low. Mailchimp provides guidance on how to avoid abuse complaints through their policies.

Key opinions

• Gmail's FBLs: Many marketers note that Gmail does not provide a traditional feedback loop, meaning complaint data from Gmail may not be visible in standard reporting.
• Unsubscribes as indicators: A common opinion is that high unsubscribe rates, even without high complaint rates, can signal underlying issues with list engagement or consent.
• Inboxing vs. complaints: Some believe that improved inboxing can paradoxically lead to more visible complaints, as emails that previously went to spam now reach the inbox where users can mark them as unwanted.
• Brand recognition is key: Marketers frequently emphasize that if subscribers were unaware of an acquisition, or if branding shifts, it can lead to confusion and increased complaints.
• Consent re-evaluation: Many recommend actively re-establishing consent for acquired lists, especially when facing deliverability issues.

Key considerations

• Engagement segmentation: It is vital to segment acquired lists based on engagement levels to identify and target active subscribers, as outlined in our advice on improving deliverability with unengaged lists.
• Proactive list management: Focus on consistent list management and engagement to prevent complaint rates from escalating. Regular list hygiene is crucial.
• Permission pass for dormant lists: For acquired lists, sending a permission pass campaign or a re-engagement series is a recommended strategy to confirm recipient interest and to re-engage a dormant email list with high spam complaints.
• Brand clarity: Even if using the old brand name and domain, transparent communication about the acquisition within the email content can reduce confusion and complaints.
• Continuous monitoring: Keep a close eye on all engagement metrics, including opens, clicks, unsubscribes, and bounces, to identify trends and potential issues early.

Key opinions

• FBL complaint confirmation: Experts confirm that Mailchimp's reported high complaint rates are indeed FBL complaints, indicating recipients manually hitting the spam button.
• Complaint rate threshold: While 0.1% is a common threshold for elevated complaints, many experts consider rates of 0.05% or 0.07% to still be too high, signaling potential issues.
• Unexpected mail: If complaints are high even when the sender's name hasn't changed, it suggests recipients either don't want the mail or it's unexpected, possibly due to a lack of prior notice about the acquisition.
• List age impact: An older list, especially one without performance history, is likely to generate not only complaints but also significant bounce issues.
• Consent re-evaluation: Re-establishing consent after an acquisition is frequently advised by experts, especially when dealing with unknown list quality.

Key considerations

• Re-engagement strategy: Experts suggest implementing a permission pass or re-engagement campaign to clean the list and permanently suppress disengaged subscribers. This can help recover email deliverability after sending to a purchased list.
• Bounce analysis: Don't just remove soft bounces automatically. Analyze bounce reasons; for example, 'no MX record' bounces should be permanently removed, while 'full mailbox' might warrant a temporary pause and retry.
• Reputation alignment: Consider that mailing an acquired list can negatively affect your existing sender reputation. It may be beneficial to initially use the old infrastructure for re-engagement and only migrate truly active subscribers. For specific ISP concerns, review how to improve email deliverability to Microsoft.
• Domain reputation: Any action that leads to high complaints can impact your domain reputation, affecting all future sends. Regularly check your sender reputation to ensure consistent performance.

Key findings

• Complaint definition: Documentation (e.g., Mailchimp) defines abuse complaints as direct reports from recipients marking emails as spam, which are then relayed to the sender via FBLs.
• Impact of complaints: High complaint rates significantly damage sender reputation, leading to increased spam folder placement, throttling, and even blocklisting (or blacklisting) by ISPs.
• Consent is paramount: Explicit consent for email communication is a fundamental requirement across almost all platforms and legal frameworks (e.g., GDPR, CAN-SPAM). Acquired lists often fall short of this standard for the new sender.
• List hygiene: Regular cleaning of email lists, including removing inactive subscribers and invalid addresses, is a universally recommended practice to prevent complaints and improve deliverability. This can be supported by understanding how your email address ends up on a blacklist.

Key considerations

• Dedicated abuse address: Many sources advise setting up a dedicated abuse@ email address to centralize and manage complaint data, allowing for direct investigation and resolution.
• Subscriber experience: Prioritizing the subscriber experience and ensuring emails are expected and relevant reduces the likelihood of complaints. This means maintaining clear branding and managing expectations during transitions (like acquisitions).
• Monitoring deliverability metrics: Beyond complaints, documentation often stresses monitoring a holistic set of metrics, including opens, clicks, unsubscribes, and bounce rates, to get a comprehensive view of list health and deliverability. For more detail, see a practical guide to understanding your email domain reputation.
• Authentication standards: Proper setup of email authentication protocols like SPF, DKIM, and DMARC is crucial for establishing sender credibility and reducing spam classifications, as detailed in a simple guide to DMARC, SPF, and DKIM.