This guide explains what email deliverability is and gives seven practical tips to improve it, for marketers and businesses whose emails are landing in spam or not arriving at all.
Have you ever wondered why some of your emails never reach your subscribers?
According to a 2021 report by EmailToolTester, the average email deliverability rate is 83.1%. This means that about 17% of emails never reach their intended recipients.
That’s why email deliverability is so important. Ensuring your emails reach subscribers can significantly improve your email marketing efforts.
Email Deliverability Checklist At A Glance
Tip
What it fixes
How to check it
1. Write non-spammy subject lines
Spam filter triggers and low open rates
Review subject lines for spam trigger words, excessive caps and punctuation, and run inbox placement tests
2. Keep clean email lists
Bounces, inactive addresses and spam complaints
Track bounce and complaint rates and remove invalid or long-inactive contacts
3. Warm up your IP address
Blocks and throttling when a new IP sends high volume
Increase volume gradually and watch delivery and bounce rates at each step
4. Check your sender reputation
Mail filtered because of poor reputation
Use tools such as Google Postmaster Tools and blocklist checkers
5. Avoid spam traps
Blocklisting caused by sending to trap addresses
Never buy lists, use confirmed opt-in and remove addresses that never engage
6. Authenticate your email domain
Spoofing and mail rejected for failing authentication
Verify SPF, DKIM and DMARC records with a DNS or authentication checker
7. Perfect the opt-in process
Fake sign-ups, typos and unwanted subscribers
Test your sign-up form and confirm subscribers with double opt-in
What Is Email Deliverability?
Email deliverability determines the ability of your emails to land in the intended recipient’s inbox, rather than getting stuck in spam folders or bouncing back altogether. It includes metrics such as open rate, CTR, spam rate, etc.
High email deliverability is important for several reasons:
Visibility: If your emails end up in the spam folder, your audience won’t see them.
Engagement: High deliverability increases the chances of your emails being opened and read.
Reputation: Good deliverability helps maintain a positive sender reputation, which is essential for future email campaigns.
How To Improve Your Email Deliverability
If you are not satisfied with the performance of your email campaigns, you might need to take some steps to address this issue. However, it’s important to start by analyzing the data and determining what areas need improvement.
We also recommend utilizing deliverability test tools like Snov.io to check your email account and ensure your sender repudiation always stays on top.
We’ve combined an email deliverability checklist. Save it, and feel free to refer to it whenever you work on your email outreach.
1. Write non-spammy subject lines
Subject lines are the first thing recipients see. When writing good subject lines, focus on the genuine value of the message without sounding pushy or salesy because they determine whether your email will be opened, marked as spam, or simply ignored by the recipient.
Tips on writing effective subject lines:
Be clear and concise: Make them straight to the point and engaging.
Avoid spammy expressions: Words like “Free,” “Urgent,” and “Buy Now” can trigger spam filters. Although ISPs have become more sophisticated in their filtering systems, avoiding these common spam phrases is wise.
Personalize: Use the recipient’s name, role, or company to make the email more personal.
Make them engaging: Use subject lines that pique interest without being misleading. Then close with a clean, professional ending using email sign offs.
2. Keep clean email lists
This is crucial for email deliverability. You don’t want to spend your time and efforts on invalid email accounts.
Tips for maintaining clean email lists:
Regularly remove inactive email addresses: Perform email validation regularly to detect and remove invalid or inactive email addresses, which reduces high bounce rates and improves email deliverability.
Use double opt-in: Make sign-ups a two-step process. This verifies email addresses and reduces the chances of typos or invalid entries.
Segment your lists: Divide recipients based on different segmentation factors such as their interests, industry, role, etc.
Avoid purchased lists: Resist the temptation to buy email lists. These often contain inaccurate or irrelevant addresses, hurting your deliverability rates.
3. Warmup your IP address
This helps build a good sender reputation. Gradually increase your email-sending volume to establish trust with Internet Service Providers (ISPs).
A properly warmed-up IP address signals to ISPs that you are a legitimate sender, which can significantly improve your email deliverability over time. To simplify this process, many teams rely on email warmup software, which gradually increases sending volume while monitoring engagement and reputation.
Step-by-step guide on how to warm up an IP address:
Start small: Start with a small number of emails, for example, 40 per day. Do not send 100+ emails in one day, as it may increase the risk of being temporarily blocked by your ESP.
Gradually increase volume: Slowly and steadily increase the number of emails sent daily.
Monitor performance: Track open rates, bounces, and complaints.
4. Check your sender reputation
Sender reputation is a score Internet Service Providers (ISPs) give based on your email-sending volume. A high score means better deliverability and a higher chance that your emails will reach subscribers’ inboxes.
Factors that affect sender reputation:
Bounce rates: High bounce rates, especially hard bounces from invalid addresses, can harm your reputation.
Spam complaints: Frequent spam complaints lower your reputation. Ensure your content is relevant, make unsubscribing easy, and use double opt-in to confirm subscribers’ interest.
Volume: Sending too many emails in a short period of time can hurt your reputation.
Blacklists: Getting banned by major ISPs severely impacts your reputation. Avoid practices that can lead to blacklisting, like sending emails to purchased lists or using misleading subject lines.
5. Avoid spam traps
Spam traps are email addresses used to detect and catch spam accounts. If you send emails to such accounts, your deliverability will most likely worsen.
Tips on how to avoid spam traps:
Maintain permission: Only add contacts who have explicitly opted in to receive your emails. An easy unsubscribe option in every email shows respect for your subscribers and helps maintain list quality.
Use a reputable ESP: A good ESP offers spam filtering and reputation monitoring features. They can also help you avoid known spam traps.
Stay up-to-date: Learn about the latest anti-spam practices and regulations.
6. Authenticate your email domain
Email authentication verifies that your emails are sent from a legitimate source, improving deliverability. Here are the primary methods of email authentication:
SPF (Sender Policy Framework):
Purpose: Specifies which IP addresses can send emails on behalf of your domain.
How it works: Add an SPF record to your DNS settings listing authorized IP addresses. Recipient servers check this record to verify legitimacy.
Benefits: Reduces spoofing and phishing risks, enhancing trust and deliverability.
DKIM (DomainKeys Identified Mail):
Purpose: Adds a digital signature to emails, verifying their integrity.
How it works: A DKIM key pair is simply generated, and the public key is added to your DNS—the private key signs outgoing emails, which recipient servers verify using the public key.
Benefits: Ensures email content and sender authenticity, boosting deliverability.
Purpose: Specifies how unauthenticated emails should be handled and provides reports on authentication results.
How it works: You create a DMARC policy in your DNS that instructs recipient servers to handle emails failing SPF or DKIM checks. The policy also sends reports on these activities.
Benefits: Offers visibility into email authentication, prevents unauthorized domain use, and improves deliverability through policy enforcement.
7. Perfect the opt-in process
A proper opt-in process ensures you have permission to email subscribers, reducing spam complaints and improving deliverability.
If you email people who weren’t aware or didn’t agree to receive your messages, your emails will be marked as spam, and ISPs will think you’re spamming everyone on your list.
Best practices for an effective opt-in process:
Use double opt-in: Implement a double opt-in where subscribers confirm their email via a link, ensuring genuine interest and preventing fake sign-ups.
Clear privacy policy: Clearly state how you will use subscribers’ data and what emails they will receive. Transparency builds trust and reduces future complaints.
Easy unsubscribe: Include a visible unsubscribe link in every email, making it simple for subscribers to opt out and maintaining list quality.
Use captcha or verification questions: Incorporate Captcha or simple verification questions to ensure real people subscribe, maintaining list integrity.
SPF, DKIM And DMARC Explained
These three DNS-based standards prove to mailbox providers that your emails really come from you. Gmail, Yahoo and other major providers now expect bulk senders to use them.
SPF (Sender Policy Framework): a DNS record that lists the servers allowed to send email for your domain. Receiving servers check the sending IP against this list.
DKIM (DomainKeys Identified Mail): adds a cryptographic signature to each message. The receiving server checks it against a public key in your DNS to confirm the message was not altered and was authorized by your domain.
DMARC (Domain-based Message Authentication, Reporting and Conformance): tells receivers what to do when a message fails SPF or DKIM alignment (none, quarantine or reject) and sends you reports on who is sending mail as your domain.
Authenticate your domain with SPF, DKIM and DMARC, keep your list clean, and send only to people who opted in. Warm up new IPs and domains gradually, keep complaint and bounce rates low, and write subject lines and content that do not look like spam. Monitor your sender reputation and inbox placement so you catch problems early.
What is a good email deliverability rate?
Aim for as close to 100 percent as you can; many marketers treat a rate above 95 percent as healthy. Remember that delivery rate (accepted by the server) is different from inbox placement (landing in the inbox rather than spam). Watch inbox placement, bounce rates and spam complaint rates together.
Do SPF, DKIM and DMARC improve deliverability?
Yes. They prove to mailbox providers that your mail is legitimate, which protects your domain from spoofing and helps your messages pass filtering. Major providers such as Gmail and Yahoo require them for bulk senders, so missing records can lead to messages being rejected or sent to spam.
Conclusion
This article covered key strategies to improve email deliverability, including understanding its importance, writing non-spammy subject lines, keeping clean email lists, and many more.
Consistently following these best practices is essential. By implementing these tips and monitoring your email performance, you can ensure your emails reach your subscribers’ inboxes and effectively engage your audience.
