Introduction
Email marketing continues to be one of the most effective ways to engage with customers in 2025. However, even the best emails sometimes end up in the spam folder. The purpose of email marketing is to reach out to clients and potential customers, nurture leads, and turn one’s audience into recurring and paying customers. Email marketing can only be a success if email deliverability is optimized.
The purpose, however, can be defeated if your emails do not reach the correct folders. Email deliverability is crucial to the survival and thriving of email marketing campaigns. If your emails are not delivered, you are cut off from the client — and you will not be able to sell your products, not because your emails were terrible, but because they were not seen.
Key Points
Quality Over Quantity: Don’t flood inboxes. Fewer, high-quality emails make a better impression.
Keep It Real: Speak like a human, not a corporation. Authenticity builds trust.
Know Your Audience: Tailor your message. Different readers, different interests.
Clean Your List: Remove inactive subscribers. Keep it fresh, keep it relevant.
Avoid Spam Triggers: Avoid “Buy Now!” and similar phrases. Use natural language instead.
Build Trust: Use the same sender address and avoid suspicious links. Consistency matters.
Let’s explore email deliverability and how to prevent your email from going to spam.
1. Email List Health
Your email list contains all the email addresses you send messages. A good list contains only active emails. A bad list contains inactive and unsubscribed emails. When you consistently send emails to inactive people or people who will eventually mark your email as spam, you run a risk of hurting your reputation.
Tools like Outreach Magic can help you maintain a healthy list by identifying bad email addresses. Outreach Magic gives you the power of monitoring and tracking in real time. With such power, you know who opens your emails, clicks your links, and who sends your emails to the spam folder.
How to collect a healthy email list
To maintain a healthy email list, you must first filter how you gather your emails. While buying a list isn’t entirely bad, it opens you up to strangers who will not hesitate to send your emails to the spam folders. However, when you gather your list from genuine marketing efforts, you will most likely interact with people who are familiar with your brand/company and are willing to communicate. Also, remove all inactive and unsubscribed emails from your list.
Collect your list through legitimate campaigns from social media efforts, paid advertisements, physical events, and webinars.
Free seminars and webinars are also a great way to turn non-paying customers into paying customers. Give out a freebie, collect emails, and start your campaigning process.
Identify the largest customer clusters in your industry and localization.
2. Sender Reputation
The sender reputation for your email and IP address can determine where your email will fall. A good sender reputation means following ESP rules for email marketing and outreach. Factors that affect sender reputation include click-through rate, open rate, spam triggers, and IP reputation.
The click-through rate (CTR) is the rate at which people click the links in your emails. A high CTR shows that people trust you, and hence, ESPs will trust you. Open rates are measurements of the number of people that open your email, frm the total number of emails sent. Again, a high open rate signals to ESPs that people trust you.
As an email marketer, you must pursue reasonable-to-high CTR and open rates. You can start by ensuring that you warm ESPs before sending bulk emails. By warming, you send emails to your most active recipients first, and increase the number of emails in a single send batch.
3. Authentication Protocols
Email authentication is important in ensuring your emails are connected to email servers. It also serves as a security patch. Protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) verify your IP address.
Setting up these protocols protects your emails from malicious actors and scammers. Not only are authentication protocols important for deliverability, they protect you. Without them, ESPs will likely flag your email as spam. We know terms like DKIM and SPF may sound complex, but they aren’t. With Outreach Magic, authentication is simplified, and can be done in less than 5 minutes.
4. Engagement Metrics
As we explained previously, engagement metrics report how many people open, click on links, or respond to your email. Low engagement metrics will negatively impact your email campaigns. High metrics show that your IP and email addresses are reputable, reducing the chances of ending up in the spam folder.
A high open rate shows that people value your content, which boosts your deliverability. However, a high bounce rate or low engagement sends the opposite message. Focus on segmenting your email list to target the most interested recipients.
Hence, you should always monitor your email campaign performance. The reports may surprise you, and help you objectively tweak directions for better ROI.
5. Email Content Quality
Content plays an important part in email marketing. The more you send engaging content that triggers a response, the more likely your emails will end up in recipients’ primary folders. For example, consistently sending salesy content can push you into the promotions tab. Sending emails that always urge customers to make purchases can be considered spammy (especially from a domain and IP that has not earned a high reputation).
The different types of content for email marketing
Informative and educative content (Industry-targeted): These are content meant to teach customers and potential customers how to navigate, not just the tool, but the industry. For example, a financial institution may send its users emails on how to better protect themselves against scammers and hackers.
Informative content/user guide: These are content meant to educate users and potential users on how to navigate the tool.
Salesy content: Meant to sell.
While salesy content leads the customers to the landing page or the pricing page, you should also favor informative content, as it builds trust.
6. Domain and IP Reputation
Your domain and IP address affect deliverability when sending emails. If your domain is new or has a poor reputation, email servers may mark the email as spam. Similarly, sharing IP addresses with spammers can affect your reputation, even if you are not a spammer. Sharing IP with unknown people can be dangerous to every other infrastructure connected to the IP address.
To avoid this, send emails from dedicated IP addresses if possible. If you’re using a shared IP, choose a provider with a good reputation and minimal risk of spammers.
7. Frequency of Sending
Sending too many emails in a short period can cause your reputation to drop, while not sending enough can result in low engagement rates. Find a balance that works for your audience.
The key here is consistency. You risk overwhelming recipients if you send emails too often or in bursts. If you’re just starting out, gradually increase your email sending volume and stay steady. Even if you have a long email list, you should be ready to run an IP Warming exercise to ensure that ESPs trust your IP address.
8. Cold Emails and Spam Traps
Cold emailing can be a double-edged sword. If done right, it’s a great tool. However, if you’re sending emails to people who haven’t opted in, you could be flagged as a spammer.
Spam traps are another issue. These are email addresses created specifically to catch spammers. If you send emails to these addresses, you’ll be flagged by spam filters. It’s essential to use targeted campaigns and permission-based email marketing to avoid these traps.
According to recent statistics, 40% of cold emails never reach the inbox, primarily due to poor list hygiene and spam traps.
9. Personalization and Relevance
Personalized emails tend to perform better and prevent your email from going to spam. Not only does personalization make an email stand out, but it also shows the recipient that you understand their interests. Addressing a recipient by name, offering recommendations, or tailoring content to their preferences can increase engagement.
Irrelevant emails, on the other hand, can result in high bounce rates and unsubscribes, which directly affect your deliverability. Keep your emails focused on what the recipient wants, not what you want to promote.
Again, how you gather your email will help in classifying recipients into suitable categories. It’s important to classify recipients as you run your email campaigns, as this ensures that you use recent and relevant data.
10. Responsive Design
With mobile users on the rise, it’s essential to design emails that look good on all devices. Responsive design ensures that your emails are readable on smartphones, tablets, and desktops alike.
A poor mobile experience can cause recipients to delete your email without engaging with it. In turn, this leads to lower open rates and poor engagement metrics. Always test your emails on different devices before sending them out.
11. Compliance with Email Laws
In 2025, email marketers need to be aware of global privacy laws, like the GDPR in Europe and the CAN-SPAM Act in the U.S. Non-compliance can affect your reputation and lead to hefty fines.
Ensure your emails include a clear unsubscribe option and you’re not collecting data without consent. One of the best ways to prevent email from going to spam is to ensure that your email gathering process complies with strict rules. Keep records of your opt-in processes to ensure you comply with legal requirements.
Following the laws doesn’t just help the recipients; it improves your reputation with ESPs. ESPs are the gatekeepers for your recipients. If ESPs find out that you do not comply with necessary global laws, they may blacklist or block your IP address and email address.
12. Fraudulent Emails and Scams
Fraudulent emails have become more sophisticated in recent years. Phishing emails that impersonate legitimate companies are a growing concern. These emails can damage your brand’s reputation if they’re tied to your domain or email address.
Educate your subscribers about identifying scams and be vigilant about protecting your own systems. Implementing two-factor authentication and keeping your security protocols up to date will help reduce the risk of fraudulent activities affecting your email deliverability.
On the other hand, you should not engage in fraudulent email collection. While you may earn some business from that, nothing beats loyal and organic customers who love your product/service.
Ensuring Email Deliverability: Conclusion
Maintaining good email deliverability in 2025 requires attention to detail and a commitment to quality. By understanding and addressing these factors, you can maximize the chances of your emails being delivered successfully. Whether cleaning your email list or implementing the latest authentication protocols, each factor plays a vital role in ensuring your email reaches the inbox. Stay proactive, and keep your strategies updated to stay ahead of the game.
Struggling with email deliverability? Outreach Magic helps businesses ensure their emails land in the inbox—not the spam folder.
