What is Cold Email Deliverability?

Learn about the importance of cold email deliverability for salespeople by reviewing our email deliverability checklist. And learn about our email warm up tool while you're at it too!
To ensure the success of your cold email campaigns, provide smooth email deliverability.

Consider this: your emails will be much less likely to be opened or read if they end up in the spam folder.

Therefore it’s important to have proper email deliverability.

Everything you have to know about cold email deliverability will be explained in this article.

Cold Email Deliverability - Definition

Cold email deliverability refers to the ability of an email to successfully reach its intended recipient's inbox without being marked as spam or rejected by the recipient's email server.

In other words, it is the likelihood that your cold email will actually be delivered to the recipient's inbox and not filtered out by spam filters or blocked by the email server.

Deliverability can be influenced by several factors such as the quality of your email list, the content and structure of your email, your sending reputation, and your email service provider.

What Affects Cold Email Deliverability?

Lack of Proper Authentication

Most of the time, email filtering algorithms on the receiving end mark undeliverable cold emails as spam or phishing emails.

This occurs when algorithms do not successfully confirm the email is authentic and comes from a reliable sender address.

You can use one of three email authentication techniques to ensure your cold emails are delivered to the inbox: SPF, DKIM, and DMARC.

We will cover more about this in the next section.

Spam-Trigger Words

Email providers identify certain words or phrases as spam-trigger words. These terms are frequently present in emails that recipients mark as spam.

If something seems too good to be true, it probably is, as the saying goes. Spam filters pick up suspicious words and phrases that are usually connected with scams, free gifts, schemes, etc.

Modern spam filters are more intelligent than ever. If you use the words "limited time" or "get started now," they won't instantly mark your message as spam.

But if you use many spam keywords in your email or write everything in Caps, bright red fond, and with several exclamation points, you’re very likely to end up in spam.

Low Engagement Rates

If your emails have a low open rate and reply rate and, with that, a high bounce rate, your deliverability will be bad.

The reason for low open and reply rates can be a lack of personalization in your cold email strategy.

If your subject line doesn’t interest your prospect, they will probably delete your mail or mark it as spam in the worst case.

Same counts for the main body of your cold email. Using sales-y language will probably make your prospects close your mail right away.

Trying to start a conversation in normal and objective language while simultaneously showing that you understand your recipients' pain points will increase your reply rate.

How to Improve Cold Email Deliverability?

Check Your Email Provider Limits

Each email service provider sets their own daily and hourly caps on the total amount of messages that can be sent. If you exceed such limits, your account is often disabled for at least a few hours. Your mailbox may be permanently banned in specific circumstances.

For instance, Gmail, under Google Apps for work, offers daily sending caps for free and paid mail accounts.

If you don’t work with Gmail, do this:

Find out who your email provider is and look in their help section for information regarding daily sending limits. If you can't find any clear information, ask the provider directly about their daily and hourly sending limits.

Also, check out our blog post about how many cold emails to send per day to have a clearer picture.

Set Up a Separate Email Domain For Outbound

You should have at least two domains since you don't want to harm your main domain, which is usually connected to your website.

It would be careless to use this domain for cold outreach. This is because all email addresses from a domain will be marked as spam once their reputation is bad.

Set up a second domain to provide your sales team with the ideal setting for cold outreach.

Your domain names should be as similar to one another as possible. Your email domain might not be compatible if you have two extremely distinct domains.

Also, having an email subdomain for more specific departments inside your company will help you have your day-to-day more organized
Improve your email deliverability with Unfiltered.ai

Check For Spam-Trigger Words

Words typically used in spammy email offers should not be included in any portion of your email.

Naturally, you won't be flagged as spam if you use the word "marketing" once in your email.

But consider how often you use these words in your messages. Surely, there is a non-sales-y approach to representing your good or service.

What's in it for your recipient?

It should be addressed briefly but precisely in your value proposition.

Just watch out for wording and expressions that are used to sell.

Never attempt to sell in any of your follow-up emails or cold emails.

Make sure to maintain a personal yet professional tone throughout the emails.

Keep the Format as Simple as Possible

Avoid attempting to make it appear exotic by including HTML templates, images, gifs, vibrant fonts, and other visual effects.

Spam filters that assess the text-to-HTML and picture-to-text ratio prefer plain text emails because they appear more authentic.

Your email will appear suspicious and may be spam if it has less plain text than the rest.


The key objective is establishing credibility and trust using SPF, DKIM, and DMARC.

Making sure SPF authentication techniques are applied is a good place to start if you want to improve your cold email deliverability. Domain owners can provide a list of IP addresses and domains allowed to send emails on their behalf using the Sender Policy Framework (SPF).

When SPF is configured correctly, email receivers can have confidence that spam will be rejected or quarantined, allowing legitimate messages to be delivered as intended.

DKIM (DomainKeys Identified Mail) works with SPF to verify that the sender is accountable for the content by putting a signature in each outgoing email. Prospects are more likely to believe your firm when they discover its emails are digitally signed, improving your organization's reputation.

Your cold emails will be given a higher rating the more times they are reviewed and properly validated.

Senders can comprehend what receivers view thanks to DMARC (Domain-based Message Authentication, Reporting, and Conformance), which gives recipients information about the message.

The best way to prevent email abuse like spam, phishing, and spoofing is to employ all three strategies—DMARC, SPF, and DKIM.


Cold emailing is essential to any B2B sales and marketing strategy. It’s especially important to target prospects not yet aware of your brand.

However, to be delivered properly, your emails must go through spam filters and into the intended inboxes.

You must avoid spam triggers, such as your from address, subject line, and content.

If you keep these things in mind, you should be able to create effective cold emails that get through spam filters and into the intended inboxes.

You can use Unfiltered to ensure your deliverability is high enough to send cold emails and stay high for the future.

Unfiltered is an email warm-up tool that automatically increases the deliverability of your mailbox and guarantees your cold emails will be delivered to the recipient's inbox.
Related articles
Improve your email deliverability now.
email deliverability