Email Deliverability Checklist 2024: Avoiding Sender Blacklist With Best Practices
Written by
Auroshik Das

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Email Deliverability Checklist 2024: Avoiding Sender Blacklist With Best Practices

Published : August 31, 2023 | Updated : May 14, 2024

Email deliverability is arguably the biggest worry when deploying email marketing campaigns. And it’s definitely a matter of concern, given the stringent filtering that happens before emails land in your inbox. Nearly 1 of every 5 emails often fails to reach the recipient’s inboxes.

With evolving spam filters and increasing email clutter, even well-crafted campaigns risk being flagged as spam, hurting deliverability rates. Remember, it’s NOT just about hitting “send”; it’s about guaranteeing your emails land smack dab in your target audience’s inboxes.

Hence, this blog post will crack the code for following industry best practices. This includes gauging the latest updates by Google and Yahoo in 2024 w.r.t. authentication protocols like SPF, DKIM, and DMARC while equipping you with the critical metrics to track the campaign’s success, industry-grade best practices to boost deliverability and subsequent open rates, lead conversion, sales, and ROI.

What is Email Deliverability?

Imagine sending a message in a bottle across a vast digital ocean. Email deliverability is the unseen current that ensures your message reaches the intended shores – your subscribers’ inboxes. 

In simpler terms, it’s the number of emails that successfully land in the inbox vs the total number of emails sent.  Whenever you hit “send,” email deliverability determines if your message sails smoothly or gets lost at sea. It’s a crucial metric for any marketer, as reaching inboxes is the first step to engagement and conversion.

A higher deliverability rate indicates a greater success rate in reaching your subscribers’ inboxes and avoiding spam filters. A good email delivery rate is usually higher than 95%.

Email Deliverability Vs Email Delivery

Many often tend to confuse email deliverability with the term email delivery. While both “deliverability” and “delivery” sound similar and involve getting emails to your audience, there’s a critical distinction between them. Let’s delve into how it differs from email delivery and what causes their failures.

Email Delivery

Refers to the physical transmission of an email from the sender to the recipient’s mail server, regardless of where it ends up (inbox, spam, etc.).

  • Example: You send an email newsletter, and it successfully reaches the recipient’s email server at Gmail.
  • Causes Of Failure: This can occur for several reasons, including invalid domain names, nonexistent email addresses, or blocked IP addresses. Your email bounces back in these cases, never reaching the intended recipient.

Email Deliverability

Concerned with the email landing in the intended destination, which is typically the recipient’s inbox after successfully bypassing spam filters for the recipient to see.

  • Example: Your email newsletter reaches the recipient’s Gmail server and avoids spam filters, ultimately landing in their inbox folder.
  • Causes Of Failure: This happens when technical glitches, poor reputation, irrelevant content, or bad email lists get your messages labeled as spam, preventing them from reaching inboxes.

Why Does Email Deliverability Matter So Much?

With the total number of email accounts totaling 4.3B globally in 2023 and email marketing generating $42 for every $1 spent, every email lost in the spam abyss represents a wasted opportunity.

With a high email deliverability rate, your carefully crafted marketing messages have a much better chance of landing in inboxes, not spam folders. This translates to more opens, clicks, and conversions, boosting ROI. 

Imagine your investment in crafting an email campaign is wasted because it never reaches its target audience. Nobody wants that. By prioritizing deliverability, you ensure your message gets seen, maximizing the potential return on your email marketing efforts.

Top 10 Tips For Better Email Deliverability

Email deliverability isn’t a one-trick pony – many factors influence it. While a mistake can land you in the spam folder, you can consistently improve your email deliverability rate by identifying and addressing missteps. Hence, here is a list of the top 10 industry-grade practices for a robust deliverability structure.

1. Maintain Sender Reputation

Maintaining a positive sender reputation is crucial for good deliverability. This acts like a credit score for emails and ranges from 1 to 100. Like a good credit score gets you approved for a loan, a strong sender reputation ensures your emails reach inboxes.

Usually, a 70+ score is sure to get you good inboxing. A low score will flag you as a spammer, resulting in more rejections and bounces to spam folders.


Also read: How you can recover from a bad sender reputation.


2. Implementing Authentication Protocols

Authentication protocols like SPF, DKIM, and DMARC establish your email’s legitimacy and help prevent spoofing and phishing attacks. They also improve deliverability when you implement them correctly.

Implement these to build trust with email providers like Google and Yahoo, boosting your chances of landing in inboxes without being labeled as spam to junk folders.

3. Crafting Relevant & Engaging Content

Content is king, even when it comes to deliverability. Create compelling subject lines, avoid spam triggers, and keep the design unique. Strike the right balance between promotional and informative content to prevent your messages from being marked as spam.

Avoid misleading subject lines, sales language, and off-topic content. Focus on recipient expectations to build trust and boost deliverability.

Here’s a blog to give you a more comprehensive picture.

4. Optimize Image Utilization

While visuals can enhance your emails, an excessive number of images compared to text content can negatively impact deliverability. Aim for a healthy balance and ensure images are compressed to avoid large file sizes.

5. Practice Permission-Based Listing

Build a clean email list through permission-based marketing. Wasting time and money on purchased or scraped lists of inactive subscribers and invalid addresses leads to high bounce rates, ultimately hurting your domain reputation. Regular list cleaning removes these risks, ensuring your emails reach real people who want to hear from you.


Also read: 6 Proven Email Segmentation Strategies to Drive Customer Engagement


6. Develop A Frequency Finesse

Bombarding subscribers one day and then wholly being silent for long periods will affect your deliverability. Develop a strategic sending cadence that provides value without overwhelming your audience.

7. Warm Up Your IP Reputation

If you’re using a new IP address to send emails, gradually increase your sending volume to establish a positive reputation with email providers. A sudden surge in emails from a new IP can be a red flag affecting deliverability. Consider dedicated IP solutions like Netcore if you send high volumes of emails.

8. Monitor & Analyze Your Results

Analyze key email metrics like bounces, unsubscribes, and clicks through your ESP’s analytic tools to identify areas for improvement.

High bounces? Clean your list. Spikes in complaints? Refine content. Low clicks? A/B test subject lines. This consistent monitoring and action ensures your emails land in inboxes, boosting engagement and avoiding the spam folder.

9. Prioritize Mobile-Friendly Design

47% check email on phones! Ensure your emails are responsive and render well across different screen sizes. A good mobile experience can reduce unsubscribes and help your deliverability.

10. Utilize a Reliable Email Service Provider (ESP)

An ESP acts as the gateway between your business and the user’s inbox;  it is, therefore, vital to select a reliable and reputed provider. A good ESP will offer robust email infrastructure, dedicated IP addresses, load balancing, bounce handling, list hygiene, email feedback loops, detailed analytics and reporting, and scalable server capacity to handle high email volumes and yet maintain consistently high deliverability.

The right ESP will stay up to date with industry best practices and evolving email deliverability standards. They will proactively adapt their infrastructure and processes to ensure optimal deliverability, helping you stay ahead of any technical challenges.

Unmasking the Top 8 Email Deliverability Myths

Misconceptions, often disguised as convenient tactics, can lead to sending practices that ultimately send campaigns astray. Persistent myths, like the belief that high email frequency equates to success or the existence of universal spam trigger words, have unfortunately fueled these detrimental strategies.

This section serves as a guide, dispelling the top 8 email deliverability myths and ensuring your messages reach their intended destination – the prospect’s inbox.

Myth 1: Activity Targeting Is The One Stop Solution For Everything

While activity targeting – where emails go only to openers – improves bounce and complaint rates and might seem like a deliverability cure-all, it’s just a first step. Proper optimization requires a multi-pronged approach, including working with deliverability experts to identify and address deeper issues that standard user engagement metrics can’t catch.

Myth 2: 100% Deliverability Should Be The Ideal Benchmark

Marketers dream of perfect inbox placement, but undeliverable addresses (bounces, blocks, deferrals) are inevitable in email lists.  Once accepted for delivery, your emails face complex filtering algorithms. They analyze past recipient engagement to ensure that wanted messages reach inboxes while unwanted ones get relegated to spam. 95% or higher is usually considered a good score, with a bounce rate at most 3%.

Myth 3: Unsubscribe Means Bad Omen

Don’t panic about unsubscribing – they signify healthy list hygiene.  High rates indicate engaged users managing their inboxes, which are far preferable to spam complaints.  Focus on where unsubscribes spike to identify uninterested contacts or poorly timed campaigns. Offer preference centers to let users adjust communication frequency, keeping valuable leads engaged.

Myth 4: More IP Addresses Guarantees Better Deliverability

Spoofing deliverability with multiple IP addresses fails in the long run! It’s a temporary solution ISPs can detect. Address the root cause – improve your email content and permission practices. What goes through the IP matters, not the IP itself. Fix your sending practices, not your address.

Myth 5: Short Subject Lines Should Be Preferred

Subject line length isn’t one-size-fits-all. While studies suggest 41 characters (7 words) is optimal, test different lengths based on your brand, audience, etc. Use A/B testing tools like Netcore AI-powered Subject Line Optimization (SLO) to see which subject lines resonate best with your subscribers.

Myth 6: Only My Email Service Provider(ESP) Is At Fault

Blaming only your ESP for poor email deliverability is not the solution! Some ESPs rely on shared IPs with spammy senders, ultimately affecting your scores as well, but at the same time, a brand’s poor sending approach, such as en masse broadcasting or no CTAs, is also to be blamed.

Always choose an ESP that offers options like dedicated IPs to isolate your brand’s reputation. Ultimately, improving your email practices is a collaborative effort, not a finger-pointing game.

Myth 7: One Universal Set Of Spam Laws Apply Everywhere

There is no such thing as a single set of spam laws to have ever existed. Regardless of the location, one has to comply with local laws like CASL (Canada), CAN-SPAM (US), or EU Opt-In. Also, get permission (single or double opt-in, depending on regulations), offer a working unsubscribe option, and be honest with clear subject lines and a physical address. It’s the law and good practice, too!

Myth 8: Authentication Is Enough For Emails To Land In Inbox

While authentication with SPF, DKIM, and DMARC builds trust with mailbox providers (MBPs) and recipients, it’s not a guaranteed ticket to the inbox. Spammers can authenticate, too! Consider it one piece of the email deliverability puzzle – vital but not the only factor.

Demystifying Google And Yahoo Email Policy Changes

Why Are These New Rules Being Implemented?

While proper email authentication has long been a best practice, only some use it. This leaves room for spoofing and hurts everyone –  senders (damaged reputation) and users (phishing attacks). To combat this, Google and Yahoo are mandating authentication for bulk senders, making inboxes safer for all.

What Are The New Bulk Sender Requirements?

1: Email Authentication Requirements

The new rules raise the bar for email security. Google and Yahoo now require bulk senders to use SPF, DKIM, and DMARC– a trifecta of authentication protocols. This “well-established best practice,” as Google calls it, closes security loopholes and protects everyone from spoofing scams. While it might seem complex, proper authentication is vital for a positive inbox experience.

2: Monitoring Spam Rates

Staying below a 0.3% reported spam rate is now vital to deliverability. This stricter threshold by Google and Yahoo means keeping your content relevant and engaging to avoid the dreaded spam folder.

3: Unsubscribe Requirements

New guidelines require bulk senders to include a clear and easy-to-find unsubscribe link. This makes it faster for recipients to opt out, ultimately boosting both deliverability rates (by reducing spam complaints) and engagement (by giving users control). Google even recommends specific headers for one-click unsubscribe functionality. Also, unsubscribe requests must be addressed within two days.


Download: Compliance checklist for bulk email senders.



Remember, it’s not about blasting emails but crafting targeted messages that land in inboxes and resonate with your audience. Prioritizing deliverability maximizes the impact of your email marketing efforts, drive engagement and engagement for your business, and ultimately boost your ROI.

Here’s why choosing the correct ESP for high deliverability matters:

  • Long-term investment in your reputation: High deliverability builds trust and strengthens your brand image with every email in an inbox.

  • Maximize campaign effectiveness: Stop wasting resources on emails that never get seen. High deliverability ensures your marketing efforts reach their full potential.

  • Drive revenue and growth: Convert more leads, boost sales, and watch your ROI soar with successful email delivery.

Netcore, a leader in this category, should be your ideal choice. We have been consistently ranked as a top choice by and Gartner Peer Insights, with over 6,500 businesses trusting us to send over 35  billion emails monthly.Ready to break free from email marketing purgatory?  Connect with us today and discover how our expertise and experience can help you craft email campaigns that get seen, clicked and results!

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Written By: Auroshik Das
Auroshik Das
I'm a passionate marketer with over two years of experience in the B2B SaaS space, particularly in MarTech, and I focus on crafting compelling narratives that showcase diverse business growth opportunities. By aligning these narratives with our product offerings, I have helped position our solutions for success with companies globally.