How to Send Cold Emails Without Getting Blocked

Find out what causes email accounts to get blocked when sending cold emails and learn best practices for avoiding getting in trouble with your cold emails.
Considering that cold emails are like the daredevils of the digital communication world – daring, bold, and a tad rebellious. They're your chance to reach potential customers, but it's a slippery slope, my friend.

One wrong move, and your emails might find themselves in the dreaded land of spam filters and blocked accounts.

Fear not! Writing cold emails may seem like tiptoeing through a field of digital landmines, but armed with the right tactics, you can emerge victorious. In the magical realm of this blog post, we're about to unravel the secrets and best practices that will transform your cold email game.

Get ready to dive into the art and science of sending cold emails without triggering the wrath of spam filters. It's time to be bold, be smart, and conquer the inbox!

What is a Cold Email?

A cold email is an unsolicited communication method where personalized emails are sent to individuals with whom there has been no prior interaction.

This outreach strategy is commonly employed in various business contexts to engage potential prospects.

The primary objective behind sending cold emails is to establish a connection with these prospects, with the ultimate goal of converting them into paying customers. For instance, suppose you operate an IT services company seeking to expand your client base.

In this scenario, launching a targeted cold email outreach campaign can prove instrumental in generating qualified leads and boosting your overall sales.

What is Deliverability?

Deliverability is all about making sure your cold emails actually land in the inbox and don't get caught up in spam filters. To boost your chances, keep things straightforward and follow some basic rules.

First off, use a valid email address and make sure your emails pass the spam filter tests. Using a professional tone and a well-crafted subject line helps too, as it keeps you from getting flagged.

When sending cold emails, always include a clear call to action and only reach out to folks who've said they want to hear from you. Keep your email list clean by checking it regularly.

And here's the key: keep an eye on your email deliverability rate. This helps you spot any problems and fix them ASAP. By sticking to these tips, you up your chances of getting your cold emails where they need to go, without getting blocked by spam filters.

Why do Email Accounts Get Blocked by Sending Cold Emails?

The idea that sending cold emails automatically gets your email account blocked is a bit off. In reality, sending cold emails itself doesn't lead to blocks.

If your email account does get blocked, it's not about sending cold emails; it's likely because you broke some rules. For instance, if your emails keep getting marked as spam or tossed into the spam folder by the people you're emailing, your email service provider might step in and block your account, thinking your emails aren't on the up-and-up.

5 Reasons Why Your Email Account Gets Blocked

5 Reasons Why Your Email Account Gets Blocked

1- Unnatural Sending Pattern

When your email account shows an unnatural sending pattern, it's like waving a red flag. Email providers notice when things seem a bit off. So, if you suddenly start sending a crazy amount of emails or if your sending behavior looks really different from what's usual, it might trigger the spam detectors.

Imagine this: you've been sending a few emails here and there, and then all of a sudden, it's like you hit the turbo button and start sending way more than usual. To email providers, this looks fishy. It's like going from zero to a hundred in the blink of an eye. They might think, "Hmm, this isn't the usual way this person sends emails," and that's when the risk of getting blocked kicks in.

So, the key is to keep things steady and natural. Don't go from 0 to 100 in a second – it's about finding a pace that makes sense and doesn't raise any eyebrows on the email provider's end.

2- Ineffective Email Authentication

Alright, let's break down why an email account might hit a roadblock due to ineffective email authentication.
Imagine you're sending a letter, and you want the recipient to know it's genuinely from you. You'd sign the letter or maybe use a unique stamp to show it's legit. Email authentication is pretty much the digital version of that.

It involves adding special codes to your emails, kind of like a digital signature. These codes tell the email providers that you're not an imposter and that your emails are safe and sound. The three main players in this authentication game are SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance).

SPF is like the return address on an envelope, stating which servers are allowed to send emails on your behalf. DKIM is your email's personal stamp, ensuring it hasn't been tampered with during delivery. DMARC is the supervisor, setting the rules for SPF and DKIM and helping prevent any email trickery.

So, if you neglect these digital signatures, it's like sending a letter without a return address or a signature. Email providers might get a bit skeptical because they can't be sure it's really you. That's when they might decide to put the brakes on your email account to keep things secure. So, always make sure your email authentication game is on point to avoid any unnecessary roadblocks.

3- Using Spam-Trigger Words

When your emails contain words commonly associated with spam, it sets off alarm bells. It's a bit like trying to chat with a friend about your awesome deals, but every other word is something like "free," "guarantee," or "urgent."

Email providers pick up on these patterns, and if they see too many red-flag words, they might think, "Hmm, this looks a lot like spam," and that's when they might decide to block your account.

So, the trick is to keep it clean and avoid those spammy words. It's like having a conversation without constantly shouting out things that grab attention for the wrong reasons. By steering clear of these trigger words, you're giving your emails a better chance of reaching the inbox without any detours.

4- Noy Verifying Your Email List

Neglecting to verify your email list can lead to potential trouble with your email account.

Consider your email list as your guest list for a party. If you forget to double-check who's coming and let in uninvited guests, things can get messy. Similarly, when you send emails to addresses without verifying if they're active and interested, you're inviting problems.

Unverified email addresses can bounce, marking your emails as undeliverable. Email providers see this as a sign that your list isn't well-maintained, and it raises questions about the quality of your outreach. If too many emails bounce, providers might think, "This sender isn't keeping their list up-to-date," and that's when they might decide to give your account the red light.

So, just like you'd make sure your party guests are on the list, ensure your email list is in tip-top shape. Regularly verify it to guarantee you're sending messages to the right people who actually want to hear from you. This way, you reduce the chances of your emails taking an unexpected detour to the blocked zone.

5- Not Warming-Up Your Email Account

When you send a storm of cold emails without warming up your account gradually, it's like doing a cannonball into icy water – it can be shocking. Email providers notice these sudden spikes in activity, and if they sense something unusual, they might hesitate to let your emails swim smoothly into inboxes.

Using an email warm-up tool is like dipping your toes in before taking the plunge. It helps establish a friendly rapport with email providers, signaling that your emails are on the level. Without this warm-up, providers might see your sudden email activity as a bit too much, and that's when they might decide to throw a block party for your account.

So, take a moment to wade into the email pool slowly. Use a warm-up tool to let email providers know you're here for a friendly swim, not a sudden splash that raises suspicions. This way, you pave a smoother path for your emails to reach their intended destinations without hitting a chilly blockade.
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12 Best Practices to Send Cold Emails Without Getting Blocked

1- Opt for a Trusted Email Service Provider

To kick off successful cold email outreach, make your first move by selecting a trustworthy Email Service Provider (ESP).

Reputable ESPs come armed with advanced algorithms designed to spot spam and phishing attempts, and they play by the rules set out in email laws and regulations. This choice is pivotal because a good ESP can help determine if your emails have that spammy look.

Equally crucial, a reputable ESP assists in building trust with the ESP of your recipients, making you appear as a genuine and reliable sender in the vast realm of email communication.

Example: Google Workspace (formerly G Suite)

Google Workspace is a prime example of a trusted ESP. It not only offers a user-friendly platform but also boasts robust spam filters and compliance with stringent email regulations. The credibility of the Google brand adds an extra layer of assurance that your cold emails are more likely to be recognized and accepted by recipients' email systems.

With features like DKIM and SPF authentication, Google Workspace enhances email security, reducing the risk of your emails being flagged as spam. Choosing a well-established and widely used ESP like Google Workspace sets a solid foundation for successful cold email outreach.

2- Implement Robust Email Authentication

Ensuring robust email authentication is a cornerstone of effective email deliverability.

This involves configuring SPF, DKIM, and DMARC records.

For those new to the game, SPF validates that the sending server is authorized to dispatch emails on your domain's behalf, DKIM adds a digital signature ensuring your email's integrity, and DMARC provides an additional layer of authentication and reporting.

Implementing these protocols isn't just a techy chore; it's a trust-building exercise with Email Service Providers (ESPs). It significantly reduces the risk of your cold emails being flagged as spam, making your outreach efforts more credible and effective.

3- Gradually Warm Up Your Email Account

When creating a new email account or ramping up your email sending volume, it's like stepping into a delicate dance – do it abruptly, and you might step on some toes, especially those of Email Service Providers (ESPs).

Suddenly cranking up your email sending volume sets off alarms for ESPs, making them wary of potential spam activity. This caution can lead to your emails taking a detour to the Spam folder rather than the coveted Primary inbox.

To avoid this misstep, it's crucial to warm up your email account. Think of it as a gentle introduction before hitting the main stage. Start by sending a small number of emails per day and gradually increase the volume over time. It's like easing into the rhythm instead of jumping in with both feet.

Consider reaching out to already engaged contacts before diving into your cold email outreach campaign. This not only signals to ESPs that your email account is the real deal but also helps build a positive sender reputation, improving the deliverability of your cold emails.

So, before you hit the cold email dance floor, warm up those email moves slowly and steadily to ensure a smooth performance and applause-worthy email delivery.

4- Curate a Highly Targeted Prospect List

Sending cold emails to a broad audience won't give you the results you want.

Invest time in research to create ideal customer profiles, understanding your prospects' needs, interests, and pain points.

This information helps you personalize your cold emails, improving engagement while minimizing the risk of being marked as spam.

After creating this focused list, one crucial step remains before launching your cold email outreach – verifying the email addresses of your prospects.

This step is essential because sending cold emails to invalid or inactive addresses can increase your bounce rate, harming your sender's reputation and affecting cold email deliverability.

On the other hand, verifying email addresses in advance ensures your emails reach your recipients' inboxes, eliminating the risk of bounced emails.

5- Validate Email Addresses Prior to Outreach

Before diving into your cold email outreach, take a moment to validate those email addresses.

Why? Well, sending emails to addresses that are invalid or inactive is like mailing letters to the wrong house – it won't get you anywhere.

Validating email addresses is a smart move. It helps trim down your bounce rate, which is crucial for maintaining a solid sender reputation. When your emails are sent to verified and active addresses, you're not just avoiding the annoyance of bounced emails, but you're also ensuring that your outreach efforts are more effective and well-received.

So, before hitting that "send" button on your cold email campaign, double-check those addresses. It's a simple step that goes a long way in enhancing the success of your outreach efforts.

6- Insert Personalization into Your Email Content

Personalization is the secret sauce for successful cold email outreach.

To nail this, invest time in understanding your recipients and customize your cold emails accordingly.

For a personalized touch, address each prospect by their name, weave in specific details about their interests or industry, and show genuine interest in helping them overcome challenges.

This practice goes beyond just connecting; it builds trust and boosts engagement, minimizing the chances of your email account facing the dreaded block.

So, when it comes to cold emails, remember, it's not about volume anymore; it's about relevance and the personal touch you bring to each interaction.

7- Steer Clear of Spam-Trigger Words

When crafting cold emails, steer clear of spam-trigger words that set off spam alarms. Common culprits include “Free,” “Guaranteed,” “Urgent,” “Deal,” “Discount,” “Sale,” and the like.

Opt for clear, concise language that exudes professionalism, helpfulness, and relevance. This not only sidesteps spam filters but also elevates your campaign's overall performance.

Sending cold emails is a potent way to connect with potential customers, but the key is doing it right to avoid spam filters.

Here are some essential tips:

  • Subject Line Caution: Skip words like 'urgent' or 'important.' They can be red flags for spam filters.
  • Tone it Down: Steer clear of excessive exclamation marks and capital letters; they may signal spam.
  • No Clickbait: Resist using clickbait phrases like "Get it now" or "Don't miss out!" They can come off as aggressive and trigger spam filters.
  • Avoid Aggressive Language: Words like "act now" or "you must" can raise eyebrows. Opt for a more engaging and friendly approach.
  • Mind Your Attachments: Too many images or attached files can be viewed as spam. Keep it simple and focused on content.

Remember, good content always triumphs over spam-trigger words. Prioritize meaningful, valuable communication to ensure your cold emails resonate positively with recipients.

8- Curtail the Number of Links in Your Emails

Limiting the number of links in your cold emails is a smart move.

When recipients spot an unsolicited email flooded with links, it can raise suspicions about its legitimacy. In some cases, they might even hit the spam button, spelling trouble for your email deliverability and sender's reputation.

To stay in the clear, focus on delivering valuable content and guide your prospects to a single, relevant link. This not only ensures your cold emails land in the right inboxes but also enhances the overall user experience.

And here's a golden rule: The perfect number of links to send in a cold email is 0. Keep it clean, focused, and directed for the best results.

9- Exercise Caution with Sending Volume

It's wise to keep your sending volume in check, usually under 50 emails per day per email account.

Why the restraint? It's simple – maintaining a sending volume around 50 emails per day hits the sweet spot for optimal email deliverability.

Even though many Email Service Providers (ESPs) allow higher sending limits, sticking to this 50-email threshold ensures you play it safe. If your outreach needs exceed this limit, the workaround is to utilize multiple email accounts.

10- Maintain a Balanced Text-to-HTML Ratio

Sending cold emails without risking your email account requires paying attention to a crucial factor – maintaining a proper text-to-HTML ratio.

When your email tips the scales with excessive HTML code compared to actual text content, it can trigger suspicions and, worse, activate spam filters.

To sidestep this, prioritize balanced, predominantly text-based content in your cold emails. In fact, if possible, opt for text-only content. If you need to sprinkle in some HTML, do so sparingly and only for essential formatting or visual enhancements. This strategy minimizes the chances of your cold emails triggering spam alerts, earning the trust of ESPs to smoothly pass through.

11- Incorporate an Easy Unsubscribe Option

To safeguard your email account and foster positive relationships, it's essential to include an unsubscribe link in your cold emails.

Sending cold emails always carries uncertainty about recipient interest. By providing a straightforward way for recipients to opt out, you not only respect their preferences but also adhere to legal requirements.

Respecting opt-out requests is a two-fold advantage. It not only contributes to a positive sender reputation but also helps steer clear of increased spam complaints that could potentially lead to email account blocks.

So, ensure your cold emails feature an easily accessible unsubscribe link. Swiftly processing and honoring opt-out requests not only safeguards your sender reputation but also lays the groundwork for lasting relationships with your prospects.

12- Monitor Deliverability and Key Metrics Closely

For optimal performance in your email outreach campaign, closely monitoring deliverability is non-negotiable. Keep a keen eye on your email bounce rate to gauge success.

The golden standard for an email bounce rate is 2% or less. In simpler terms, if you send 100 cold emails and encounter 2 or fewer bounces, your email deliverability remains unscathed.

Should your email bounce rate surpass this threshold, it's a clear signal to pause and verify the email addresses on your prospect list before hitting send again. Beyond deliverability, track key metrics like open rates, click-through rates, reply rates, and spam complaints.

Low open rates serve as a beacon, signaling the need for improvements in your subject lines, email content, and overall sender reputation. By keeping a close watch on these metrics, you can fine-tune your strategy for maximum impact and success in your cold email outreach.


Sending cold emails can be a potent strategy for expanding your network, connecting with potential clients, and driving business growth. However, the ever-increasing sophistication of spam filters and email blocking measures poses challenges to achieving optimal results.

In the world of cold email outreach, success hinges on quality over quantity. Take care of the technical aspects early on, such as setting up DKIM and SPF records and warming up your domain. This groundwork lays the foundation for a smooth email delivery process.

As we wrap up this guide, remember that understanding the rules and regulations regarding cold emails in your country is crucial. Once armed with this knowledge, you can confidently build a prospect list and craft emails that resonate with your audience.

In your journey to successful cold email outreach, consider using email warm-up tools like Unfiltered to streamline the warm-up process.

Ready to give it a try? Improve your cold email deliverability by starting a free trial for Unfiltered's warm up tool.
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