How to Improve Email Deliverability?

email deliverability

The tactical objective of your cold email campaign is to land your emails into your Prospect’s Primary Inbox, where they will be read and not in the Social, Promotional, or Spam folders.

Why is Email Deliverability Important?

The number of spam and phishing emails is increasing daily, so email providers are being more careful about what gets into your inbox. They’ve started using brilliant filters to catch these bad emails. Email deliverability is all about dodging these filters and reaching your prospect’s primary inbox. 

After creating an email account, you enjoy good deliverability when you send emails within your organization or to clients. It becomes an issue when a cold email campaign is launched with the same account. The emailing behaviors have changed, and the number of emails going out has drastically increased. Such behavior triggers the spam filter. 

All follow-ups will land there if your initial email goes to the primary inbox. 

Emails in the spam folder are less likely to be opened and read. Common sense, no? By ensuring good email deliverability, you increase the chances of recipients engaging with your content. This leads to more responses, which eventually turn into sales. 

Note: Never start a cold email campaign with your primary email domain. If you have one started, then please stop it immediately. Set up a secondary domain for cold emailing.

Factors Affecting Email Deliverability

When you hit send, Email Service Providers (ESPs) check a bunch of stuff before your email lands in your prospect’s inbox. Factors affecting your email deliverability are:

  • Sender Reputation: This is like your email reputation score. If prospects open and engage with your cold email, your sender’s reputation is good. But if your emails often get marked as spam or ignored, your reputation suffers. 
  • Abuse Reports/Spam Complaints: If recipients report your emails as spam or mark them as abusive, it raises a red flag. Email providers take these reports seriously. 
  • Sending Volume: Email providers want to prevent spammers from flooding inboxes, so they monitor sending volume closely. If you usually send 15 emails a day and suddenly send 300, it might look suspicious to email providers.
  • Blacklists: Email providers maintain lists of known spammers’ IP addresses. If your sending IP is on one of these blacklists, your emails will likely be marked as spam. 
  • Text-to-Image Ratio: Emails with too many images and very little text can resemble spam. Spam filters might flag such emails.
  • Number of Links: Excessive links in an email, especially if they lead to suspicious websites, can trigger spam filters 
  • Text-to-HTML Ratio: Emails that are too heavily formatted with HTML and lack plain text can be flagged as spam. If your cold email is mostly fancy graphics and design, it might be seen as spam. 
  • Spam Triggering Words: Certain words and phrases in your email content can trigger spam filters if used excessively. Words such as scams, promotions, or explicit content. Using phrases like “Act Now,” “Guaranteed,” “Limited Time Offer,” or “Winning Lottery” frequently in your email content can also trigger spam filters.
  • Unverified Email List: Sending emails to unverified or purchased email lists can significantly impact your email deliverability. As these lists may contain outdated or invalid email addresses, increasing the likelihood of bounces and spam complaints. 

All these technical factors work together. You can’t just fix one and ignore the rest. They rely on each other to ensure your emails are safe and get to where they should be. So, paying attention to these technical details is crucial for successful email delivery.

How to Increase Email Deliverability?

Some guidelines improve your chances of landing it in the Primary Inbox; let’s see them individually.

  • Sending volume. As a human being, if you optimize your workflow, have customizations ready, and are prepared for an email marathon, you may be able to go at about an email every 2 – 3 minutes. An email every 3 minutes means 20 emails an hour, which would be about 160 emails in 8 hours. Email Service Providers (ESPs) have certain thresholds for human sending limits; if you exceed those, you will get an error – sending limit exceeded. This is the first thing you want to look out for. Businesses that aim for high deliverability rates send less than 80 emails per day per email address.
  • If you are personalizing emails (which you should be doing), each email will appear different to ESPs, and this helps in deliverability. You can also consider changing each email’s salutation. Hi John, next email, Hello Amy. These small variations in text will also make the email look different to ESPs, improving deliverability. SmartReach has a feature called Spintax that allows you to do this: {{ Hi | Hello }} {{ first name }}
  • Email warmup about getting email providers like Gmail or Yahoo to trust you and build a good sending reputation. You want them to think, “Hey, this sender is legit!” And how do you achieve that? By playing by the rules and not rushing things. This helps you build a stellar reputation. This way, more of your emails end up in the inbox, which means more people see and read them.

    So, whether you’re using a new email address or you’ve had a tough time with emails going to spam before or constantly cold emailing, doing the warmup right is a must. Try an keep your sending email always connected to a warmup tool or always have a backup email warmed up at all times.

    You’ll find many email warm-up tools out there. Dont blindly go with the cheapest, as they could do more harm than good. Lemwarm, WarmUpYourEmail and WarmupHero are a few good tools. SmartReach provides free email warmup.
  • Spintax is a method used to make every email different. It creates multiple variations of a single email message by substituting words or phrases with alternative phrases or variations. If you send the exact same email to a large list of recipients, it can trigger spam filters. Spintax helps you generate slightly different versions of your email, reducing the chances of being marked as spam. Here is an example

Original introduction:

{%spin%}Hi|Hello{%endspin%} {{First_Name}},

Original value proposition:

{%spin%}I noticed you|We noticed{%endspin%} are interested in {{Subject}}. {%spin%}Our solution|Our product{%endspin%} can help you {{benefit}}.

Possible variations:
Hi John, I noticed you are interested in Marketing. Our solution can help you increase your brand visibility.
Hi Jane, We noticed you are interested in Sales. Our product can help you increase your top line.

Original CTA:
{% spin %}Let’s schedule a call to discuss further|Get in touch if you have any questions|Reply to this email with your availability {% endspin %}.

Possible variations:
Let’s schedule a call to discuss further
– Get in touch if you have any questions
– Reply to this email with your availability

  • DKIM Setup. When email was initially created in the 1970s, the security angle was not the main focus. Hence, the original protocol allowed anyone to send an email on behalf of anyone else. DKIM is a protocol that lets your recipient know that this email came from someone in your domain authorized to send emails. Setting up DKIM requires you to set up a DNS record. View our help page for how to set this up.
  • SPF Setup. The sender policy framework is a record that publishes which IPs are allowed to send emails on behalf of a particular domain. This is a DNS Record that has to be published for your domain.  View our help page to understand how to set this up. 
  • DMARC is a  3rd type of DNS record that has to be published for your domain. It ties the SPF and DKIM records and helps the receiving email server decide what to do with the email that arrives, which fails the SPF or the DKIM check.
  • You have no control over whether your recipient marks your email as spam. But if you give them an option like an unsubscribe link , instead of marking your email as spam, they can opt out of emails from you. This is far better than getting your email marked as spam and lowering your email’s reputation. Hence, always include an unsubscribe link in your email.

    Lately, some spam filters scan your email body for the word “Unsubscribe”. provides an option to hyperlink your unsubscribe link to text. So use “Not now,” or “Not Interested,” or “Stop Sending” with a link to unsubscribe

  • That brings us to spam email itself. Emails marked as spam will rapidly harm your domain’s reputation, and all your emails will soon go to the spam folder. Even one email out of a thousand getting marked as spam puts your email domain reputation at risk. Are you using words that trigger spam filters?
  • Email address list verification: If you purchased an email address list from somewhere, it may contain email addresses that are no longer valid (the person changed companies) and some emails that are repurposed for Spam Traps. Email verification services can purify your list and give you a cleaner list with invalid emails removed. This improves your bounce rate and hence enhances your deliverability. SmartReach automatically verifies every email address before sending the email to a recipient.
  • Hi {{Fisrt_Name}},
    I have been following you on Linkedin……
    Have you ever received such an email? Its embrassing! Your purpose of personalization is defeated, and guess what the spam triggers also get activated. This should be avoided at any cost. provides a feature that auto-pauses email sending for prospects where they have identified missing or broken merge-tags.

  • Domain Email warmup. For a recently registered domain, you need to ramp up your email sending gradually. You could start with 3 – 5 emails on day one. Then, slowly, over a period of days, take up to 100 to 150 emails daily. This process is tedious to manage manually. SmartReach allows you to gradually warm up your email campaign to maximum volume over several days.

  • Imagine you are unaware that your domain has entered some renowned blacklists like MXToolBox. Your team continues sending emails. This makes it more difficult to get yourself out of that list. Hence, the faster you learn of the same, the better. You will be able to review all processes and rectify the issue. SmartReach pauses the campaign when found on the renowned blacklist and notifies you immediately.

In summary, you want to monitor your spam rate, sending volume, and first-time sending for a new domain. Additionally, you want to personalize your emails, verify your email address list, and ensure you have an unsubscribe link. Finally, you want to be sure you have done your technical setup correctly for your domain – DKIM, SPF, and DMARC DNS records.

SmartReach provides you with reports on emails marked as spam and bounce rates. It also has features to personalize email via Spintax and merge tags from your uploaded data. SmartReach can be set to ramp up your sending volume gradually for newly registered domains and will automatically verify and clean your mailing list before sending emails to them. Finally, our support articles on DKIM, SPF and DMARC setup should have you moving on this front.

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