Improve Email Deliverability Using These 16 Hacks in 2025

In this article, I will tell you how to improve email deliverability for your cold email campaigns.

if you think pitching your product to your ideal customer would give you a high open and reply rate, you are wrong.

Your email may get delivered but it may land in the spam or promotion folder. I am sure you might have encountered this and are worried about how to get over this. Landing in either of the folders will not give any results to your email outbound campaign.

In this article, I will show you how to avoid that issue and increase your email deliverability.

Let’s start by understand what are the factors that affect email deliverability so you can avoid them altogether next time.

What are the factors that affect email deliverability in a campaign?

There are many factors that could influence your emails ending up in spam and it differs for email clients like Google, Outlook, Yahoo, etc.

Each of these email service providers has different algorithms to categorize emails as spam. And the factors that influence these algorithms will have different weightage in the algorithm.

Here’s an overview.

Lack of proper technical configuration 👎🏼

If you have not configured important email protocols such as SPF, DKIM and DMARc then there is a high chance of your emails landing in the spam folder as it would indicate that your email is not trustworthy. Get this sorted asap. This article will help you with setup of SPF, DKIM, DMARC

Sending high volume of cold emails from day 1 👎🏼

Sending a huge volume of emails is one of the main reasons why emails land up in spam folders. This is mostly overlooked by someone who is eager to start the cold email campaign.

Spammy email content 👎🏼

Your email content is another factor that affects email deliverability.

Are you sending the same content to multiple recipients without any changes?
Does your email copies include spammy or promotional keywords such as “exclusive”, “Free”, “limited”?
Are the links you have added in your email body getting clicked?
Are the prospects actually replying to your email sequences?
Is it getting marked as spam?
Are your email getting unsubscribed too frequently?

Email service providers such as Google, Outlook, Apple Mail etc. notice all these things and accordingly mark your emails for inbox placement or for SPAM. Avoid these spam-trigger words in your email copies.

Invalid prospect list for outreach 👎🏼

The quality of the prospect list also matters.

If the list has too many invalid email addresses with outdated information about the prospects you are targeting, there will be low or no email engagement and the overall email deliverability will be affected.

Usually invalid email addresses result in high email bounce rates, which affect lower your sender reputation and deliverability.

Other reasons that affect email deliverability 👎🏼

Apart from the above main reasons there are some other reasons that often cause emails to land in spam instead of the primary inbox of the recipients, such as –

Using too many direct links in the email copy. Beware even if you are hyperlinking more than twice per email copy.
Using personal email addresses to do cold emailing.
Using too much HTML content in your email content.

How to improve email deliverability for cold email campaigns?

If you are planning to use cold email on a long-term basis then there are some best practices that should be followed to improve email deliverability.

Now, there are countless different ways to avoid spam folder, but remember most of them stand on one simple rule: “Be genuine and provide value“.

Let’s look at the various tips below to improve email deliverability for your cold email campaigns.

#1 Configure SPF, DKIM and DMARC record for your system

Getting a Sender Policy Framework (SPF) record ensures that the emails are being sent by you and not being forged. This ensures that the email address is being trusted by the email service providers. Setting up SPF allows email servers to cross-check your domain name against your associated IP address to make certain that you’re legitimate.

A DKIM, Domain Keys Identified Mail is an electronic signature to outgoing message headers using the DKIM standard. It’s basically a way to verify that your email is absolutely being dispatched by you, and not a hacker. Without DKIM, there will always be a risk of your email being tampered and content being changed.

Having a DMARC, Domain Message Authentication Reporting & Conformance policy tells the email service providers that the email is being protected by SPF and DKIM. Without DKIM policy, there is a high chance that your email would land in a spam folder and would be marked as untrustworthy. Both of these things improve your deliverability.

Once you set-up all your email authentication records properly, it will improve email deliverability to an extent of 20-30%.

Learn how to set-up your DKIM here.

#2 Validate your email list before sending emails

Also know as email verification, email validation is a process of how to check if an email is valid.

Doing it manually is a tiresome and time taking process.

You can use an email verifications tool to do this faster. Cold email software like SmartReach.io offers unlimited email validation for free. It auto-verifies every email before you start sending emails to those addresses.So, it will improve email deliverability in the long-run.

#3 Check for spammy words in your email content

Verify your email content and make sure that it does not include any spam filter-triggering words. Make sure to keep it simple, straight and to the point. Make sure your email content provides something of value.

Tip: Keep the email subject line within 3-4 words and the body copy within 5-6 lines for the maximum engagement.

#4 Send unique email content to each recipient

Make sure you are not sending the same generic email content to each prospects in your email list. Otherwise, it will catch spam and seem uninteresting to your prospects.

Use a Cold email software like SmartReach.io that provides features like spintax which makes every email content unique. You could also use upto 5 variants of subject lines for testing which one performs better. This way no two emails will every be the same

#5 Adhere to privacy laws and guidelines

Adhere to important privacy laws such as CAN-SPAM, CCPA, GDPR and the organisational privacy rules for sending emails to the prospects.

For example to be CAN-SPAM compliant, you should:

Avoid fake or misleading information (such as offering an impossible benefit)
Do not overuse words like “sale”, “free”, “promotion”, etc.
not make use of too many “! “s in your email messages
Be open and honest with respect to your intentions (is the one simple rule)
Avoid using lots of images (none is better)
Simply by using a little common sense, your outreach goes a long way.

Similarly take action according to the other privacy laws before you start your email outbound process.

#6 Build genuine connections instead of just trying to “sell”

Focus on providing value first and building associations with the target prospects instead of going all in for selling.

When you assist someone, the individual feel good, they’ll help you. Call it reciprocity or whatever you will – it’s just human trait to help those we like.

There are countless ways you can make people feel great:

Comment on their websites with something meaningful
Share and like their work
Make them get in touch with someone in your network
Send them a handwritten note of gratitude
Direct a client to them

#7 A/B test your email campaign regularly

Using some generic cold email templates you found from the internet is a good starting point, however, they can not give your maximum engagement and deliverability in the long-run.

Every industry is different with unique paint points and motivations.

If you would like to improve cold email deliverability and ROI, you need to keep testing the emails on a regular interval.

SmartReach’s A/B testing feature helps understand which format works the best for maximum email engagement and deliverability. This way you learn the content type that your audience is engaging with and scale your outreach gradually.

Here are some elements you can A/B test in your cold email campaigns:

Email subject lines
Email body copy
Call to action
Email signatures
Value proposition in your email copies
email sending times
Adding an image versus none
ICP and buyer persona

#8 Check for blacklists every week

Regularly check if your emails and IPs are getting blacklisted. Being on the blacklist will keep your emails from ever reaching a prospect’s primary inbox. To see if you’re on any blacklists, you can use a free tool like MX Tool Box.

This blog on how to get off an email blacklist can help understand the whole process behind getting off emails from blacklist. Read that to find more.

SmartReach users are automatically notified and their campaigns are auto-paused if they become a part of a serious blacklist. This helps you take corrective action and save you from getting your domain ruined further.

#9 Try to keep the number of attachments low in the emails

Avoid including attachments in your emails for cold email campaigns. This is the best solution.

If any important attachment needs to be sent, hyperlink it to the right keyword in the email copy or send it in your email follow-up sequence. Its always best to keep your first email clean.

No links and no attachments.

Remember, if your first email is delivered to the primary inbox then the entire sequence will reach there.

#10 Keep your daily email sending limits low

Send fewer emails, when you are starting with a cold outreach campaign.

Gradually ramp up sending but not more than 40 to 50 emails per email account per day and not more that 2000 emails per domain per day. This thumb rule will keep you on the safe side.

Check out the email sending limits across ESPs to find the daily email sending limits in details.

Email automation platform SmartReach that provides features like campaign soft start to achieve the gradual ramp-up. Also, with its free email warm-up tool Warmup Hero you can start your email warm-up process without paying extra for any tool.

#11 Schedule your emails at different times

If all your daily emails are being sent at a single time then it might look suspicious. Also, it will not fetch the best engagement due to the geographical time differences of the different prospects.

Email sending can be automated and scheduled all through the weekdays to check how your emails perform on each day of the week in terms of overall engagement and deliverability.

SmartReach provides time-based email scheduling as per the timezone your prospects are in for the maximum engagement and deliverability. So, you to reach the right person at the right time

#12 Add a strong email signature to your email copies

Add an email signature may be a strong one, in case your lead wants to get familiar with you and your content before they respond.

This also helps in driving organic traffic to your recent posts. It also creates a sense of trustworthiness. Prospect should be able to check your credibility.

We have covered the best practices you should follow in your email signature in this article. Make sure to read it to before you create an email signature for yourself.

#13 Avoid click & open tracking in your email campaigns

Try to avoid tracking email open and click through rates. Although it might be tempting but until it is absolutely necessary, do not enable the tracking.

When open tracking is enabled, a small tracking pixel in the form of an image is fired and when link tracking is enabled a redirect is added to your links which enables your email software to track links.

If these images and redirects get caught by the spam filters then your email will end up in the spam folder. Keeping this off will improve email deliverability in the long run.

#14 Focus on email personalization

With personalization, every email you send looks natural and relevant to the recipients.

Using email personalization would show the email service providers that the email is being legit and written by a human and it would prevent getting caught by the spam filter. Also, personalization would prompt your prospects to open and reply to your emails.

For example, you use merge tags to add personalization such as the name of the prospect, company, location, job title, any specific achievements etc. SmartReach provides the option to add unlimited custom merge tags in your email copies.

#15 Include a visible option to unsubscribe

Irrespective of the email content, not everyone would be happy to receive the email.

Having an unsubscribe link is better than a prospect marking your email as spam. This will help you keep the spam complaints and email deliverability high.

SmartReach users can hyperlink any custom keywords like “Not Interested” or “Stop Sending” into unsubscribe links within a few clicks.

#16 Use a cold email software to improve email deliverability

Cold email software is quite different from email marketing software. Email marketing software such as Mailchimp, Sender or Sendinblue are not designed for cold email outreach. When such tools are used cold emailing, there is a high chance of your domain getting blacklisted, getting blocked and your account getting disabled.

Email marketing software are designed for bulk marketing promotions like sending newsletters, promotions, and transactional emails. The idea is to reach thousands or even millions of customers in a day or so. While cold email software is designed to send emails like a human. One at a time.

Technically, you could send more than 500 emails per day from one email ID but if you are looking to improve email deliverability then send less than 50 email per day per mailbox.

Simply put, cold email software like SmartReach does not replace email marketing tools like Mailchimp. These software complement each other. Cold email software like SmartReach.io are specially designed for cold email outbound process and has built-in features and processes to increase email deliverability.

SmartReach provides advanced suite of email deliverability features specially designed for sales teams of all sizes to run, manage and automate email outbound process for maximum email engagement and ROI from the outreach.

Check out the case studies to see how SmartReach increased the bottom line of the businesses belong to different industries across the world.

If you want to try and see if SmartReach.io works for your team, try this 14 Day FREE trial. (No credit card required)

Wrapping Up: how to improve email deliverability

Email deliverability is the foundation of a successful cold email outreach campaign

Of course, it isn’t the only challenge over here, having the technical set-up done, writing engaging content, receiving a good reply rate etc does also matter.

So if you are interested in running a successful cold email campaign then follow as many as steps possible and focus on quality over quantity. These are a sure shot strategies to improve email deliverability of your email outbound process.

Frequently Asked Questions (F.A.Q)

What is meant by “email deliverability?”

Email deliverability means getting your email successfully delivered to the recipient’s (your prospects) primary inbox by your email service provider.

When email exchanges happen between co-workers and friends then the email naturally lands in the primary inbox naturally. This indicates the email deliverability rate is good.

But it comes to launching a cold email campaign then your email service provider will see a change in email-sending activity.

For example, you might be sending around 15 emails per day to your co-workers, but when it increases to 200 then it would definitely affect the deliverability. When an email service provider notices an unnatural behavior in sending emails, then it would result in your email landing in the spam or promotion folder.

This would indicate that you won’t be getting a good open or reply rate. Thus there would be a decrease in sales as well.

How do you ensure email deliverability?

Authenticate your domain with SPF, DKIM, and DMARC to verify you’re a legitimate sender.
Warm up your IP address by gradually increasing email volume to build a positive reputation with email providers.
Maintain a clean list by removing bounced emails and using double opt-in for signups.
Craft clear, concise subject lines that avoid spammy triggers and offer a clear unsubscribe option in every email.
Track your email metrics and stay informed about the latest deliverability best practices.

What hurts email deliverability?

There are many elements that hurt email deliverability such as using spammy words in the email copies, not proper set-up of the email authentication records, getting too many spam complaints from the recipients etc. But if you have to focus on one single element that would to be “buying email lists” for running campaigns. These lists mostly contain outdated contact information with invalid email addresses. Sending email to these addresses just increase your bounce rates overnight and kill your email deliverability.

What is DMARC email deliverability?

DMARC isn’t directly responsible for getting your emails delivered, but it plays a critical role. DMARC works with other authentication protocols (SPF, DKIM) to verify you’re the rightful sender. This builds trust with email providers, improving your chances of landing in inboxes and avoiding the spam folder.

Is Gmail using DMARC?

Yes, Gmail participates in DMARC along with other major email providers. While Gmail itself doesn’t directly implement a DMARC policy to receive emails, it relies on senders using DMARC to verify their legitimacy. This helps Gmail fight spam and phishing attempts that try to spoof Gmail addresses.

How to fix email delivery issues?

Build a clean list with confirmed opt-ins.
Verify you’re the rightful sender.
Avoid spammy triggers, write honest & concise.
Include a clear link in every email.
Monitor metrics and stay updated on best practices.

How important is email deliverability?

Email deliverability is the foundation of any successful email outbound campaigns. If your emails aren’t reaching inboxes, your carefully crafted content goes unseen. High deliverability ensures your messages land where they belong, boosting open rates, engagement, and ultimately, the ROI of your email campaigns.

How To Improve Email Deliverability? Reach Recipients Primary Inbox

What are the factors that affect email deliverability in a campaign?

Lack of proper technical configuration 👎🏼