What should I include in an email deliverability checklist?

Key findings

• Technical setup: Proper configuration of authentication protocols like SPF, DKIM, and DMARC is fundamental for sender legitimacy and avoiding spam folders. Without these, your emails are more likely to be flagged or rejected.
• List hygiene: Regularly cleaning your email list to remove inactive subscribers, bounces, and potential spam traps significantly boosts your sender reputation and deliverability rates. This also ensures you're reaching engaged recipients.
• Engagement monitoring: Tracking key metrics such as open rates, click-through rates, and complaint rates provides valuable insights into subscriber engagement and potential issues that might affect inbox placement.
• Content quality: The content of your emails, including subject lines, body text, and links, plays a significant role in how spam filters perceive your messages. Avoid spammy language and maintain a good text-to-image ratio.
• Reputation management: Maintaining a strong IP and domain reputation is paramount. This involves consistent sending volume, low complaint rates, and avoiding blacklists. For guidance on improving your reputation, see our article on how to improve email IP and domain reputation.
• Consent and expectations: Always ensure subscribers have explicitly opted in and that your email content aligns with their expectations to minimize spam complaints.

Key considerations

• Comprehensive approach: Deliverability is a multifaceted issue that requires attention to technical setup, content, and list management. Relying on just one aspect won't guarantee success.
• Regular monitoring: An effective checklist should include routine checks, not just one-time setups. Email best practices are always evolving, as highlighted by EmailTooltester's guide to deliverability best practices.
• User experience: Beyond technicalities, consider how recipients interact with your emails. A good user experience reduces complaints and increases engagement.
• Proactive troubleshooting: Having a plan for diagnosing and resolving issues promptly is essential. Learn more about avoiding spam filters and best practices for deliverability.
• Organizational responsibility: Assigning clear responsibility for email processes internally prevents misconfigurations and ensures ongoing maintenance of deliverability standards.

Key opinions

• Subscriber consent: Marketers stress the importance of explicit consent and managing subscriber expectations to prevent complaints and maintain good sender reputation.
• Unsubscribe process: A clear, easy-to-use, and compliant unsubscribe process is essential. It's better for disengaged subscribers to leave than to mark emails as spam, which negatively impacts deliverability.
• List hygiene importance: Regularly cleaning email lists to remove invalid or unengaged addresses is a common piece of advice. Using email validation tools is a critical practice.
• Engagement tracking: Monitoring open rates, click-through rates, and complaint rates helps marketers understand how their audience is interacting with their content and identify potential deliverability issues.
• Reply management: Ensuring replies to marketing emails are read and acted upon can provide valuable feedback and improve sender reputation.

Key considerations

• Data source transparency: Marketers should have a clear understanding of where their email addresses originate and an audit trail to prove consent, as emphasized by Twilio's deliverability best practices guide.
• Sending tempo: Maintaining a consistent and reasonable sending volume helps build and maintain a positive sender reputation.
• PII responsibility: Understanding and assigning responsibility for Personally Identifiable Information (PII) within the organization is crucial for compliance and avoiding data misuse that could impact deliverability. Regularly tracking key performance indicators (KPIs) for email deliverability is also important.
• Customer service integration: Empowering support staff to handle unsubscribe requests directly can improve the customer experience and prevent unnecessary complaints.

Key opinions

• Centralized responsibility: Having one person or team responsible for email deliverability across the entire organization is critical to avoid misconfigurations and ensure consistency, especially with authentication protocols like DMARC. This helps to identify the cause of declining deliverability.
• DNS record vigilance: Even minor changes to DNS records by IT staff can inadvertently break SPF or DKIM, leading to significant deliverability issues. Regular audits are vital.
• DMARC monitoring: Implementing DMARC is not enough; experts stress the necessity of daily or weekly review of DMARC reports to identify authentication failures and unauthorized sending sources.
• Port 25 egress control: Blocking port 25 egress for all but managed MTAs (Mail Transfer Agents) can prevent rogue systems from sending unauthenticated mail and impacting domain reputation.
• Compliance and deliverability link: Poor compliance with data handling and privacy regulations often leads to poor deliverability, as misuse of customer data can result in blocks and blacklisting (or blocklisting).
• Importance of authentication: Proper email authentication with SPF, DKIM, and DMARC is a non-negotiable part of any robust deliverability strategy.

Key considerations

• Proactive monitoring: It's not enough to set up protocols; continuous monitoring is required to detect changes or issues quickly before they escalate into major deliverability problems.
• Internal education: Educating internal teams, especially IT and sales, about the importance of email deliverability and authentication protocols can prevent accidental misconfigurations.
• Data privacy impact: Mismanagement of Personally Identifiable Information (PII) can directly lead to deliverability issues, as recipients may block senders they believe are misusing their data.
• Comprehensive security: Beyond authentication, general network security measures, like controlling outgoing mail ports, contribute to overall email ecosystem health and trust.
• Continuous improvement: Deliverability is an ongoing process. Regular audits and adjustments based on performance data are necessary for sustained inbox placement. Tabular.email's checklist provides a good starting point for maintaining deliverability.

Key findings

• Authentication standards: RFCs define critical email authentication protocols like SPF, DKIM, and DMARC, which are essential for verifying sender identity and preventing spoofing. For a deeper understanding of these, explore DMARC tags and their meanings.
• Header formatting: Proper email header formatting, as outlined in RFC 5322, ensures that mail servers can correctly process and deliver messages, avoiding rejections or spam folder placement.
• SMTP error codes: Understanding and responding to SMTP error codes (e.g., 550 for hard bounces) is vital for maintaining a clean list and a good sender reputation.
• Feedback loops: Mailbox providers often offer feedback loops, which send reports of spam complaints back to senders, allowing them to remove problematic subscribers.
• IP and domain reputation: Documentation often highlights factors influencing IP and domain reputation, such as consistent sending volume, low complaint rates, and avoiding blacklists. Learn more in our in-depth guide to email blocklists.

Key considerations

• Compliance with RFCs: Strict adherence to Request for Comments (RFCs) related to email (e.g., RFC 5321 for SMTP, RFC 5322 for message format) is paramount for interoperability and deliverability.
• Regular updates: Email standards and best practices evolve. Regular review of new RFCs and industry guidelines from mailbox providers (like Google and Yahoo) is essential.
• Error handling: Implementing mechanisms to correctly interpret and act upon bounce messages and other error notifications is crucial for list health and reputation.
• Domain consistency: Ensuring consistent use of domain names across all email components (From, Reply-To, Return-Path) and aligned with authentication records helps build trust.
• Content best practices: While not always specified in RFCs, documentation from mailbox providers frequently includes recommendations on content to avoid spam filters, such as avoiding excessive links or image-only emails.