How can newsletter senders improve email deliverability?

Key findings

• Sender reputation: A strong sender reputation is the cornerstone of good deliverability. Internet Service Providers (ISPs) heavily weigh this when deciding whether to deliver your emails.
• Email authentication: Implementing DMARC, SPF, and DKIM is fundamental to proving your emails are legitimate and protecting your domain from spoofing. This helps improve trust with receiving servers and is increasingly mandated by major mailbox providers.
• List hygiene: Regularly cleaning your email list to remove inactive subscribers, bounces, and spam traps is vital for maintaining a healthy sender reputation and avoiding blacklists (or blocklists).
• Engagement metrics: High open rates, click-through rates, and low complaint rates signal to ISPs that your content is valued by recipients, positively impacting your deliverability.

Key considerations

• Content quality: Craft compelling, relevant content that encourages engagement and discourages spam complaints. Avoid overly promotional language or common spam trigger words.
• Subscriber consent: Ensure all subscribers have explicitly opted in to receive your newsletter. Using a double opt-in process is a robust way to confirm consent and build an engaged list.
• Monitoring and testing: Continuously monitor your sender reputation and deliverability rates. Utilize email deliverability tools and practices to identify and address issues promptly. For more on this, check out this guide on email deliverability best practices.
• Technical setup: Proper email authentication setup (like SPF, DKIM, and DMARC) is non-negotiable for proving legitimacy and boosting inbox placement.

Key opinions

• Engagement is key: Marketers widely agree that active engagement, such as opens and clicks, is paramount. This signals to ISPs that recipients want your emails.
• List hygiene matters: Keeping your email list clean and free of unengaged or invalid addresses is frequently cited as a top priority to prevent bounces and maintain a healthy sender reputation.
• Personalization and segmentation: Tailoring content to specific audience segments or individual preferences can boost relevance and engagement, leading to better deliverability.
• Reputation management: Actively monitoring and improving your sender reputation is seen as an ongoing task, directly tied to inbox placement.

Key considerations

• Content strategy: Focus on providing consistent value to your subscribers. Irrelevant or overly frequent emails can lead to disengagement and spam complaints.
• Unsubscribe process: Make it easy for subscribers to unsubscribe, but also try to offer options like frequency control. High complaint rates (marking as spam) are far more damaging than unsubscribes.
• Avoiding spam traps: Marketers should implement strategies to avoid spam traps, as hitting them can severely damage sender reputation and trigger blocklists. Mailchimp resources often provide good insights into maintaining list health.
• Feedback loops: Utilizing ISP feedback loops allows marketers to see who is marking their emails as spam, enabling them to remove those addresses from their list quickly.

Key opinions

• Authentication is non-negotiable: Experts consistently stress the foundational importance of SPF, DKIM, and DMARC for proving sender legitimacy and protecting against phishing.
• Sender reputation is dynamic: Your reputation is constantly evaluated by ISPs. It's built over time through consistent positive sending habits and can be damaged quickly by poor practices.
• IP and domain warm-up: For new sending infrastructure or significant volume changes, a gradual warm-up process is crucial to build a trusted sending history with ISPs.
• Proactive monitoring: Regularly monitoring deliverability metrics, blacklist (and blocklist) status, and ISP feedback loops helps identify and mitigate issues before they escalate.

Key considerations

• Feedback loop enrollment: Experts advise signing up for all available ISP feedback loops to promptly identify and remove subscribers who mark your emails as spam.
• List decay: Even highly engaged lists experience decay. Regular re-engagement campaigns and strategic list cleaning are necessary to combat this natural decline.
• Understanding ISP policies: Staying informed about specific ISP requirements, such as Outlook's new sender requirements or Gmail's rules, is crucial for compliance. Mailmodo offers expert tips to increase email deliverability.
• Domain reputation: While IP reputation is important, domain reputation increasingly dictates inbox placement for newsletter senders.

Key findings

• Mandatory authentication: Many major mailbox providers now explicitly require DMARC, SPF, and DKIM for bulk senders to ensure message legitimacy and combat phishing.
• Low spam complaint rates: Thresholds for spam complaints (e.g., typically below 0.1% to 0.3%) are strictly enforced. Exceeding these limits can lead to emails being filtered to spam or blocked entirely.
• Easy unsubscribe mechanisms: A clear, one-click unsubscribe option (List-Unsubscribe header) is a key requirement for bulk senders to comply with industry standards and legal mandates.
• Reputation management tools: ISPs provide tools like Google Postmaster Tools to help senders monitor their reputation, spam rates, and DMARC failures.

Key considerations

• Domain and IP consistency: Using consistent sending domains and IPs helps build a stable and trusted sending history with mailbox providers.
• Content best practices: Documentation often outlines content-related factors that can trigger spam filters, such as excessive links, suspicious attachments, or overly image-heavy emails.
• Regular updates: Mailbox provider policies are dynamic. Senders must stay informed about changes, such as new Google and Yahoo requirements, to maintain compliance. A simple guide to DMARC, SPF, and DKIM can help solidify your understanding of these core elements. For technical insights, consult articles on improving email deliverability from Mailgun.
• Volume and frequency: Sudden spikes in sending volume or irregular sending patterns can negatively impact deliverability, as they can be red flags for spam filters. Consistency is key.