Improve email deliverability: A checklist to avoid spam

Truth bomb: Your painstakingly crafted emails could be … worthless!

Without good email deliverability, they’ll never reach your prospects’ inbox.

In other words, all your efforts will be in vain if you don’t improve your email deliverability.

Which is why we’re introducing the finest email deliverability checklist ever created.

The checklist contains every trick in the book to improve email deliverability. Following It ensures your cold emails land in your prospects’ inboxes… consistently!

Share it with your colleagues, but not with your competitors ;-).

How to use our checklist to improve email deliverability

Our deliverability checklist gives you a quick overview of what you need to do to improve cold email deliverability.

Each item is a crucial step toward getting your emails opened, read, and replied to.

For many action items, you can follow the accompanying links to get more information.

Optimize your technical setup

The first step to achieving high cold email deliverability is making sure your technical setup is in order.

Your technical setup mainly consists of email authentication protocols that enhance email security.

Email service providers reward improved security with better inbox placement. This leads to more opens for your campaigns.

◻️ Set up your SPF record – Specifies which servers can send emails on your domain’s behalf

◻️ Set up your DKIM record – Checks if your emails don’t get tampered with during transit

◻️ Configure up your DMARC record – Determines what to do with emails that fail SPF and DKIM authentication

◻️ Set up your custom tracking domain – Use your own tracking domain instead of your ESP’s, which has a tainted reputation

◻️ Set up your exact profile (no fake names or photos) – For extra trustworthiness

Audit your sender reputation

Internet service providers track your sender reputation at both the domain and email address levels.

If your sender reputation is low, you’ll experience deliverability issues that you must fix.

But how can you check the current state of your sender reputation?

Follow these action items to get started:

◻️ Check if your email has been blacklisted – Email blacklists are lists of domains, IPs, or email addresses of suspected spammers

◻️ Check the reputation of your domain and IP – Helps give you a better indication of your domain’s health

◻️ Check your Deliverability Score with lemwarm – lemwarm is a tool that boosts and monitors your deliverability so can land in your prospect’s inbox

◻️ Analyze your current stats to get better insight

If you’re not getting enough opens and your reply rate is lower than 5%, you likely have one of the following issues:

◻️ Check if you’ve done the technical setup correctly

◻️ Make sure you’re targeting the right audience! Here’s why it’s essential to build your buyer persona for proper B2B lead generation

The best way to protect deliverability is to only email when there’s a reason to. At Rodz, we only contact leads when a signal tells us they’re likely to care — and it keeps our reputation clean and conversion high.

Peter Cools

CEO @Rodz

Warm up your email

The goal of email warm-up is build a strong sender reputation for your domain.

It involves gradually increasing email sending volume and frequency.

Here’s why email warm-up is necessary:

If you suddenly send hundreds of emails per day, email service providers may flag you as a spammer and lower your sender reputation.

But even after establishing a good sender reputation, warm-up is not over.

You must continue warming up your email to maintain your sender reputation.

You can warm-up your email in two ways:

◻️ Manual warm up (option 1 – time-consuming):

Day one: 1 email
Day two: 2 emails
Day three: 3 emails
Continue adding 1 email daily until reaching 20 emails/day

◻️ Automatic warm-up (option 2 – scalable ):

Use deliverability and warm-up tools like lemwarm to land in your audience’s inbox.

lemwarm runs 100% on autopilot and helps you:

Avoid the spam folder with a tailored deliverability strategy
Improve sender reputation with human-like conversations
Maintain high deliverability with a detailed report that shows where your emails are landing (inbox, spam, etc.)

Important: For warmup to work, your warmup emails must also get replies. Warmup tools like lemwarm automatically reply to your warmup emails.

Maintain email list quality and hygiene

Invalid email addresses can seriously damage your reputation and hurt deliverability.

Luckily, it’s easy to ensure this doesn’t happen to you.

◻️ Don’t buy email lists – Commercial email lists may contain invalid or inactive email addresses. Even worse, there could be spam traps on the list.

◻️ Always send campaigns to professional email addresses of individuals instead of generic email addresses – e.g., john@facebook.com instead of info@facebook.com or john@gmail.com

◻️ Use a system that allows you to get verified email addresses from fresh data sources consistently

Check out –> Target LinkedIn prospects, extract emails and send outbound campaigns automatically

◻️ If you have an existing list and are not sure about the data quality, use an email verifier – Some options: lemlist’s Email finder & verifier, ZeroBounce, or for small lists, lemlist’s free email checker.

Send high-quality cold emails

Email providers monitor how prospects interact with your emails.

The only way to facilitate engagement and get replies is to focus these emails on your prospects and their needs.

In other words, make them unique and well-structured.

◻️ Don’t use complex HTML! – Emails with heavy HTML and excessive styling can trigger spam filters

◻️ Don’t use fancy signatures – They can also trigger spam filters or not display correctly in all email clients

Create a clean-looking and memorable signature with lemlist’s free email signature generator.

◻️ Don’t add attachments to your emails – Attachments pose security risks and can trigger spam filters. If you need to send a file, just use links (e.g., Google Drive).

◻️ Include images if you’d like, but not too many – Check out more information on how images affect deliverability

◻️ Don’t use spam trigger words and phishing phrases – E.g., WIN, free, viagra, etc.

◻️ Don’t use ALL CAPS IN YOUR SUBJECT LINE – All caps looks unprofessional, can trigger spam filters, and make it hard to read your subject line

◻️ Always personalize cold emails – Emails with unique content look less like bulk email spam, reduce spam complaints, and boost engagement

◻️ Use liquid syntax for ultra-personalization – E.g., when you want to automatically change intro lines for different audience verticals

◻️ Use spin syntax if your lists are larger than 300 people – E.g., where you have 4 different intro lines and they will spin in random order

◻️ Always email A/B test to find out what works best for you – A/B testing allows you pit two versions of your email against each other. The winner stays on.

Maintain a good reputation

Another critical aspect of maintaining a good sender reputation is being a good guy or gal.

That means following the guidelines of email service providers:

◻️ Volume: Do not exceed your email provider’s limit – Ideally, keep the number of emails sent to 40 emails per day. If you need to deliver more emails, using multiple email accounts is best. You can do so with lemlist’s Inbox Rotation feature.

◻️ Consistency: If you suddenly go from sending no emails to blasting 500 every day, you’ll run into trouble – Establish a process with slowly increasing daily volumes instead. When you need to increase it, add one email daily and keep your warmup tool on at all times!

◻️ Reply rate: A healthy reply rate is >10% – It shows ISPs that your emails get engagement, which spam emails usually do not.

◻️ lemwarm = deliverability booster. Make sure to set up the email warm-up feature within lemlist. It will help you keep a higher ratio from email sent to email received.

◻️ Sending speed: Never send all emails at the same time – Use a system that allows you to spread them throughout the day. You can do so with lemlist and many other sales engagement platforms.

◻️ Monitor the following key metrics:

Open rate is no longer a reliable metric but you should still monitor it. Extremely low open rates may indicate a deliverability problem.
Reply rate should be higher than 10%
Bounce rate needs to be lower than 2%
Unsubscribe rate needs to be lower than 5%

◻️ Always put an opt-out link in your emails – Make it easier to click “unsubscribe” than to click the “spam” button. Spam complaints destroy your sender reputation.

Bottom line

So, what’s the main takeaway?

Never compromise on email deliverability.

It’s the first step toward outreach success.

You can have the best cold email template, the most targeted list, a killer subject line, and a crystal-clear call to action. Heck, your product might be amazing.

But it will all be in vain if people don’t see your email.

lemlist offers built-in email warm-up, real-time deliverability insights, and scalable personalization. This ensures your emails always land where they should. Try it for free today!