Summary
Achieving optimal email deliverability and avoiding spam filters involves a comprehensive strategy addressing technical configuration, list management, content creation, and reputation monitoring. While there's no magic bullet, fundamental practices include building a clean, engaged email list through double opt-in and regular cleaning, implementing SPF, DKIM, and DMARC for email authentication, segmenting lists for targeted content, maintaining a consistent sending schedule, avoiding spam trigger words, optimizing for mobile and accessibility, using a dedicated IP (especially for high-volume sending), proactively verifying email addresses, setting up feedback loops, and monitoring blocklists. Furthermore, positive engagement metrics significantly improve deliverability.
Key findings
- No Single Solution: Deliverability is a multifaceted challenge requiring a holistic approach rather than relying on a single tactic.
- Clean Email List: Building and maintaining a clean, permission-based email list is fundamental for improving deliverability.
- Email Authentication: Implementing SPF, DKIM, and DMARC records is crucial for verifying sender identity and preventing spoofing.
- Targeted Content: Segmenting email lists allows for sending more relevant and engaging content, reducing spam complaints.
- Consistent Sending: Maintaining a consistent sending schedule and volume helps build a positive sender reputation.
- Spam Trigger Avoidance: Avoiding spam trigger words and phrases in email content is essential for bypassing spam filters.
- Mobile and Accessibility Optimization: Ensuring emails are optimized for mobile devices and accessible to all users enhances engagement and reduces spam flags.
- Dedicated IP Benefit: Using a dedicated IP address provides more control over sender reputation, especially for high-volume senders.
- Proactive Verification: Regularly verifying email addresses removes invalid and risky addresses, improving deliverability metrics.
- Feedback Loop Importance: Setting up feedback loops allows for prompt removal of recipients who mark emails as spam, safeguarding sender reputation.
- Blocklist Monitoring: Regularly monitoring IP addresses and domains against blocklists helps identify and resolve deliverability issues.
- Engagement as Signal: Positive engagement metrics (opens, clicks) signal to mailbox providers that emails are valuable and wanted.
Key considerations
- Continuous Effort: Deliverability requires ongoing monitoring, optimization, and adaptation to changing email ecosystem conditions.
- Sender Reputation: Proactively manage and protect your sender reputation through consistent best practices.
- Technical Expertise: Properly implementing and maintaining SPF, DKIM, and DMARC records requires technical expertise.
- Content Quality: Focus on creating high-quality, relevant content that recipients find valuable and engaging.
- User Experience: Prioritize user experience across all devices and accessibility needs to minimize spam complaints.
- Compliance: Adhere to email marketing regulations (e.g., GDPR, CAN-SPAM) to maintain trust and avoid penalties.
What email marketers say
10 marketer opinions
To optimize email deliverability and avoid spam filters, several best practices should be followed. These include building and maintaining a clean email list with double opt-in and regular cleaning, authenticating emails using DKIM, SPF, and DMARC, segmenting lists for targeted content, maintaining a consistent sending schedule, avoiding spam trigger words, optimizing emails for mobile devices and accessibility, using a dedicated IP address for high-volume sending, verifying email addresses, and setting up feedback loops to handle spam complaints.
Key opinions
- Clean List: Building and maintaining a clean email list is crucial. Use double opt-in, remove inactive subscribers, and avoid purchasing lists.
- Authentication: Implementing DKIM, SPF, and DMARC is essential for authenticating emails and improving sender reputation.
- Segmentation: Segmenting email lists based on demographics, behavior, and engagement allows for more targeted and relevant emails.
- Consistency: Maintaining a consistent sending schedule and volume is important for sender reputation. Avoid sudden spikes or drops.
- Spam Triggers: Avoiding spam trigger words in subject lines and body content helps prevent emails from being flagged as spam.
- Mobile Optimization: Optimizing emails for mobile devices ensures proper rendering and engagement, reducing the likelihood of spam complaints.
- Accessibility: Making emails accessible improves inclusivity and signals a commitment to best practices, enhancing deliverability.
- Dedicated IP: Using a dedicated IP address provides control over sender reputation, especially for high-volume senders.
- Verification: Regularly verifying email addresses removes invalid and risky addresses, improving deliverability and engagement.
- Feedback Loops: Setting up feedback loops allows prompt removal of recipients who mark emails as spam, maintaining a healthy sending reputation.
Key considerations
- List Hygiene: Regularly clean your email list to remove inactive or disengaged subscribers. This shows ISPs you're only sending to interested recipients.
- Authentication Protocols: Ensure you implement SPF, DKIM, and DMARC records correctly and keep them updated to authenticate your emails.
- Content Relevance: Tailor your email content to specific segments of your audience to increase engagement and reduce spam complaints.
- Sending Frequency: Monitor and maintain a consistent sending schedule. Avoid sending too many emails too quickly, which can trigger spam filters.
- Mobile-First Approach: Prioritize mobile optimization to ensure your emails render correctly on all devices. A poor mobile experience can lead to spam complaints.
- Accessibility Standards: Follow accessibility guidelines to make your emails readable for everyone, including those with disabilities. This can improve overall deliverability.
- IP Reputation: Monitor your IP address reputation and address any issues promptly. A poor IP reputation can significantly impact deliverability.
Marketer view
Email marketer from Sendinblue shares that improving sender reputation requires consistent sending volume, avoiding spam traps, and authenticating emails with DKIM, SPF, and DMARC.
28 Aug 2023 - Sendinblue
Marketer view
Email marketer from Litmus shares that making emails accessible to all recipients, including those with disabilities, not only improves inclusivity but also enhances deliverability by signaling a commitment to best practices.
23 Oct 2023 - Litmus
What the experts say
9 expert opinions
Achieving email deliverability and avoiding spam filters requires a multifaceted approach. There's no single magic solution, but generally, avoiding spam-like behavior is key. Mailbox providers use algorithms, including 'trusted reporters,' to identify spam and also track engagement metrics like opens and clicks to determine email value. Monitoring IP addresses against blocklists, warming up new IPs by gradually increasing sending volume, and focusing on sending wanted content can also improve deliverability. Platforms like Hotmail also have trusted reporter programs and actively ask users about spam classification accuracy.
Key opinions
- No Magic Bullet: Email deliverability doesn't have a single, easy solution. It requires consistent effort and attention to various factors.
- Avoid Spammer Behavior: Not acting like a spammer significantly reduces deliverability issues.
- Trusted Reporters: Mailbox providers use trusted reporters and recipient tracking to identify spam accurately.
- Engagement Matters: Positive engagement, like opens and clicks, signals email value and improves deliverability.
- Blocklist Monitoring: Regularly check IP addresses and domains against blocklists to identify and resolve blacklisting issues.
- IP Warm-up: Gradually increase sending volume with new IPs to build a positive sender reputation.
- Desired Content: Sending content that recipients want is crucial, though not a guaranteed solution.
- Feedback mechanisms: Email Providers have ways of confirming whether they have correctly identified spam.
Key considerations
- Holistic Approach: Deliverability requires attention to multiple factors. Don't rely on a single 'trick' or technique.
- Recipient Perception: Focus on sending wanted content, as user engagement plays a key role.
- Reputation Management: Proactively monitor IP and domain reputation and take corrective actions when necessary.
- Gradual Scaling: When setting up new IPs, warm them up slowly to establish credibility with mailbox providers.
Expert view
Expert from Word to the Wise (Laura Atkins) explains that positive engagement metrics, such as opens and clicks, signal to mailbox providers that recipients find your emails valuable, thus improving deliverability.
23 May 2022 - Word to the Wise
Expert view
Expert from Email Geeks shares that Hotmail has a trusted reporter program for the best reporters.
23 Sep 2022 - Email Geeks
What the documentation says
4 technical articles
Email authentication is critical for deliverability. SPF records specify authorized mail servers for a domain. DKIM adds a digital signature to emails, verifying sender identity and message integrity. DMARC policies use SPF and DKIM to protect against spoofing and phishing. Reverse DNS lookup (PTR records) maps IP addresses to domain names, verifying server legitimacy.
Key findings
- SPF Authentication: SPF records authorize specific mail servers to send emails on behalf of a domain.
- DKIM Signatures: DKIM adds a digital signature to emails, ensuring the message hasn't been altered during transit and authenticating the sender.
- DMARC Policy: DMARC policies leverage SPF and DKIM to protect against email spoofing and phishing by specifying how receivers should handle authentication failures.
- Reverse DNS Lookup: Reverse DNS lookup verifies the legitimacy of the sending server by mapping its IP address to a domain name.
Key considerations
- Implementation Accuracy: Proper implementation of SPF, DKIM, and DMARC is crucial for these authentication methods to be effective.
- DNS Record Management: Regularly update and maintain SPF, DKIM, and PTR records as server configurations change.
- DMARC Policy Enforcement: Carefully consider the enforcement level of DMARC policies (none, quarantine, reject) to balance deliverability and security.
- Security Implications: Email authentication protocols are fundamental for enhancing security and trust in email communications.
Technical article
Documentation from RFC explains that reverse DNS lookup (PTR record) maps an IP address to a domain name, verifying the legitimacy of the sending server and preventing spammers from using forged IP addresses.
18 Jan 2024 - RFC Editor
Technical article
Documentation from DMARC.org defines DMARC as a policy that allows senders to indicate that their emails are protected by SPF and DKIM, and tells receivers what to do if authentication fails, helping to prevent email spoofing and phishing.
8 Apr 2024 - DMARC.org
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