What exactly is an email sender score?

An email sender score is a numerical rating (typically 0-100) that indicates the quality of your sending reputation. It helps mailbox providers assess how likely your emails are to be legitimate and wanted, influencing whether they land in the inbox or spam folder.

How often should I check my sender score?

While regular checks can be helpful, I recommend focusing more on trends in your core deliverability metrics (bounces, complaints, opens, clicks) rather than fixating on daily score fluctuations. Proactive blocklist monitoring is also important.

Can a low sender score impact my email deliverability?

Yes, a consistently low sender score can significantly impact your email deliverability, increasing the chances of your emails being filtered to spam folders or rejected outright by mailbox providers. This affects how sender score impacts email deliverability .

What role do authentication protocols play in sender score?

Authentication protocols like SPF, DKIM, and DMARC verify your email's legitimacy and prevent spoofing. Correct configuration of these protocols is fundamental to building trust with ISPs and maintaining a good sender reputation, which directly influences your sender score.

Is it possible for my sender score to fluctuate without a clear reason?

Yes, it is possible. Sender score can be influenced by various factors, including temporary network issues, isolated incidents, or even internal bugs within the scoring system. If your underlying deliverability metrics remain stable, a fluctuating score might not indicate a genuine problem.

Should I panic if my sender score suddenly drops?

While a sudden drop can be alarming, I advise checking your actual delivery rates, bounce rates, spam complaint rates, and engagement metrics first. If these core indicators remain healthy, a temporary low sender score might not warrant panic or immediate process changes. However, if your sender score has dropped and other metrics are also suffering, action is needed.

Why is my email sender score low and what can I do about it? - Sender reputation - Email deliverability - Knowledge base

Waking up to a low email sender score can be unsettling. I know that feeling of panic, seeing a score that's far lower than usual, and wondering what went wrong. My immediate thought goes to, What factors influence my deliverability? The good news is, a sudden dip in your sender score doesn't always spell disaster, but it definitely warrants investigation.

Many email platforms and monitoring tools use sender scores, like the one provided by senderscore.org, to give you an indication of your sending reputation. While a high score (closer to 100) is always desirable, it's crucial to remember that this score is just one piece of the puzzle. Other metrics, such as your actual delivery rates, open rates, and click-through rates, provide a more comprehensive view of your email program's health.

Understanding sender score and its relevance

Sender score is a numerical value, typically from 0 to 100, that reflects how mailbox providers (like Gmail, Outlook, Yahoo) perceive your IP address and sending domain. It aggregates various data points, including complaints, spam traps, rejected messages, and unknown users, to give an overall indication of your reputation. A lower score suggests a higher likelihood that your emails will be flagged as spam or blocked outright. I've heard some say it's not a useful metric, but understanding its components can still be informative.

However, it's not uncommon for these scores to fluctuate, sometimes without an obvious reason. I've seen situations where a score drops significantly, only to bounce back quickly. This can be due to various factors, including temporary network issues, isolated incidents, or even bugs in the scoring system itself. This is why I often advise looking beyond the raw score to your actual performance data. For example, some users have reported Sender Score showing inaccurate data or unexpected fluctuations.

The key is not to panic. If your deliverability rate remains high and your engagement metrics (opens, clicks) are stable, a temporary dip in sender score might just be noise. Your own internal metrics are often a better indicator of your sending health than a single, external score. Understanding how relevant sender score is to your overall deliverability is crucial for effective email marketing.

However, if you do see a low score accompanied by a drop in your inbox placement or an increase in rejections, then it's time to dig deeper. This suggests your email reputation is indeed suffering, and immediate action is required to prevent further damage.

Common reasons for a low score

While a low sender score can be a fleeting anomaly, it often points to underlying issues with your email program. Identifying these root causes is the first step toward recovery.

One of the most common culprits is a high bounce rate. If a significant percentage of your emails are bouncing (especially hard bounces, which indicate invalid addresses), it tells mailbox providers that you're sending to unengaged or non-existent recipients. This signals poor list hygiene and can severely harm your reputation and lead to your IP or domain being added to a blacklist (or blocklist).

Another major factor is spam complaints. When recipients mark your emails as spam, it's a direct signal to mailbox providers that your content is unwanted. Even a small percentage of complaints can have a disproportionately large impact on your sender score and deliverability. This is often an indicator of irrelevant content or an opt-in process that isn't clear enough.

Finally, inconsistent sending volume can also trigger alarms. Sudden spikes in volume, if not properly warmed up, can look like malicious activity to ISPs, leading to messages being filtered or rejected. This is particularly true if you are on a new sender IP address or domain.

Typical problems

High bounce rates: Sending to invalid or outdated email addresses, leading to hard or soft bounces.
Spam complaints: Recipients marking your emails as unwanted, often due to irrelevant content.
Inconsistent volume: Sudden surges in sending volume without proper ramp-up, triggering spam filters.
Poor engagement: Low open and click-through rates, indicating recipients aren't interested in your content.

Effective solutions

List hygiene: Regularly clean your lists, remove inactive subscribers, and use email validation.
Content relevance: Segment your audience and send targeted content they value.
Volume consistency: Gradually increase sending volume, especially for new IPs.
Monitor metrics: Keep an eye on opens, clicks, and bounce rates to proactively address issues.

Practical steps to improve your email sender score

If you've identified a persistent low sender score or concerning trends in your deliverability metrics, it's time to take action. I always recommend a systematic approach to fixing these issues.

First and foremost, focus on your list hygiene. Regularly cleaning your email list to remove inactive or invalid addresses is paramount. This reduces bounce rates and prevents you from hitting spam traps, which are email addresses specifically designed to catch spammers and can quickly get you blocklisted. Consider implementing double opt-in for new subscribers to ensure high-quality, engaged contacts.

Next, ensure your email authentication protocols are correctly set up and maintained. This includes Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and DMARC. These records verify that your emails are legitimate and prevent spoofing, which builds trust with mailbox providers. If you're running into issues, check your DMARC verification status.

Example SPF recordDNS

v=spf1 include:_spf.example.com include:another.spf.com ~all

Improve engagement by sending relevant, valuable content to your audience. Segment your lists and tailor your messages. High open and click rates, coupled with low unsubscribe and complaint rates, tell ISPs that your subscribers want to receive your emails, which in turn boosts your sender reputation. Conversely, low engagement can signal a problematic sender.

Finally, maintain a consistent sending volume. Avoid sudden large sends if you haven't recently sent emails at that volume. If you're a new sender or are significantly increasing your volume, warm up your IP address and domain gradually. This helps mailbox providers get accustomed to your sending patterns and builds trust over time.

Best practices for a robust email program

Regular list cleaning: Remove unengaged subscribers and invalid addresses.
Implement authentication: Ensure your SPF, DKIM, and DMARC records are correctly configured.
Engaging content: Provide value to your subscribers to boost opens and clicks.
Consistent volume: Maintain stable sending patterns to build trust with ISPs.
Monitor blocklists: Regularly check if your IP or domain is listed on any blocklists (or blacklists).

Advanced troubleshooting and long-term reputation building

Sometimes, the reasons behind a low sender score aren't immediately obvious, and you need to delve deeper. I've found that looking at the specific rejection messages from ISPs can be incredibly insightful.

For example, if you're seeing a high bounce rate specifically from certain domains, like optonline.net, you might be facing content filtering issues specific to those providers. Cable mailbox providers, in particular, can be quite strict, and their bounce messages might be vague. You would need to access your bounce logs through your email service provider to get the precise reasons for rejection. This is a crucial step for troubleshooting a dropping sender score.

Beyond immediate fixes, building and maintaining a healthy email reputation is an ongoing process. This involves continuous monitoring of your key deliverability metrics, not just the sender score. Keep a close eye on your open rates, click-through rates, complaint rates, and bounce rates across different ISPs. Tools like Google Postmaster Tools can offer valuable insights into your domain's reputation with Gmail and other providers.

Remember that a low sender score can sometimes be misleading if your delivery rate is high. It's about a holistic view of your email program.

Metric	Description	Impact on reputation
Bounce rate	Percentage of emails that couldn't be delivered.	High rates (especially hard bounces) indicate poor list quality, damaging your sender score.
Spam complaint rate	Percentage of recipients who mark your email as spam.	Even low rates can significantly harm reputation and lead to blocklisting (or blacklisting).
Open rate	Percentage of recipients who open your email.	High engagement indicates content relevance and can improve inbox placement.
Click-through rate (CTR)	Percentage of recipients who click a link in your email.	Another strong indicator of engagement and content quality.

Views from the trenches

Best practices

Actively monitor your deliverability metrics, not just a single sender score, to get a complete picture of your email health.

Prioritize strict list hygiene and regular cleaning to avoid bounces and spam traps, ensuring a high-quality subscriber base.

Consistently send valuable, relevant content to highly segmented audiences to foster strong engagement and reduce complaints.

Implement and verify all email authentication protocols: SPF, DKIM, and DMARC, as these are foundational for trust.

Maintain a steady sending volume and properly warm up new IPs or domains to avoid triggering suspicious activity alerts.

Common pitfalls

Panicking over a fluctuating sender score without analyzing underlying deliverability metrics can lead to unnecessary changes.

Neglecting to clean your email lists regularly will result in increased bounce rates and a higher risk of hitting spam traps.

Ignoring specific ISP bounce messages or content filtering issues can cause persistent deliverability problems for certain domains.

Relying solely on an email service provider's front-line support for complex deliverability issues may not provide the deep insights needed.

Sending inconsistent email volumes, especially large, unannounced spikes, can negatively impact your sender reputation.

Expert tips

Always request detailed bounce logs from your email service provider to understand specific rejection reasons from various ISPs.

Consider using dedicated IP addresses for higher sending volumes to isolate your sending reputation from others.

Proactively open tickets with Validity or other scoring services if you believe their metrics are inaccurate or inconsistent with your actual performance.

If struggling with particular ISPs, investigate their specific postmaster guidelines and consider adapting your sending strategy for those domains.

Remember that email deliverability is an ongoing effort that requires continuous vigilance and adaptation.

Marketer view

Marketer from Email Geeks says: I experienced a sudden drop in my sender score from 97 to 67, and Marketo support identified my IP as problematic, despite no apparent changes in my performance metrics or presence on any blocklists.

2024-01-08 - Email Geeks

Expert view

Expert from Email Geeks says: I don't consider sender score a useful metric and haven't for over a decade, as it often fluctuates wildly without real-world implications, making it primarily a vanity metric.

2024-01-08 - Email Geeks

Maintaining a healthy sending reputation

A low email sender score can be alarming, but it's important to approach it with a clear head. I've learned that while the score itself is a signal, it's the underlying metrics and your actual deliverability that truly matter.

By focusing on maintaining a clean email list, ensuring proper authentication, sending engaging content, and monitoring your actual delivery and engagement statistics, you can build a robust sending reputation. This proactive approach will help you navigate the complexities of email deliverability and ensure your messages consistently reach the inbox, regardless of temporary score fluctuations.