Sending Cold Emails Without Triggering Email Account Blocks: A Guide

Created On:
December 23, 2023
Updated On:
February 22, 2024
How to Send Cold Emails Without Blocking Your Email Account | Smartlead

Cold emails are 40 times more effective than social media for prospecting. But here’s the catch: you can get blocked if you are not careful enough. Writing cold emails can be daunting, but with the right approach and infrastructure, you can successfully send cold emails without getting blocked. In this blog post, we'll explore the best practices to ensure your emails are delivered without getting blocked.

What is Email Deliverability and How It Impacts Cold Email Campaigns? 

Email deliverability refers to the ability of an email to reach its intended recipients' inboxes successfully. It determining whether your emails are reaching your audience or ending up in spam folders. Successful email deliverability relies on several factors and best practices.

Firstly, using a valid email address and employing proper authentication techniques is essential. Authentication methods like SPF, DKIM, and DMARC help verify the legitimacy of the sender, increasing the likelihood of successful delivery. It's important to maintain a professional email address and create well-crafted subject lines to avoid triggering spam filters.

When engaging in cold emailing efforts, incorporating a clear call to action is crucial. Additionally, only sending emails to individuals who have opted in to receive communications from your business is vital for maintaining good deliverability. Regularly monitoring email list hygiene ensures that you are targeting an engaged and receptive audience.

Tracking your email deliverability rate is an ongoing process that allows you to identify any issues promptly. By analyzing this metric, you can assess the success of your email campaigns and take corrective action if needed. Monitoring deliverability ensures that your cold emails have a higher chance of reaching their intended recipients, contributing to the overall success of your email marketing efforts. With the right strategies and tools, you can build an effective email marketing campaign that fosters higher engagement and conversion rates.

Read more: Email Deliverability Success Stories: Insights from the Field

Why Do Email Accounts Get Blocked for Sending Cold Emails? 

There is a common misconception that sending cold emails can result in the blocking of your email account. However, the truth is that email accounts are not blocked solely because of sending cold emails. Instead, violations of guidelines and certain practices can lead to account blocks. Let’s look at the 7 reasons email accounts may get blocked for sending cold emails:

1. SPF, DKIM, and DMARC Records

Sender Policy Framework (SPF), Domain Key Identified Mail (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC) are essential records used by email service providers to authenticate senders and their emails. Failure to set up these records while sending bulk cold emails can lead to blacklisting by email service providers.

2. Multiple Recipients in CC or BCC

Including too many recipients in the CC and BCC fields can be flagged by email service providers, triggering spam filters. Monitoring the number of recipients in these fields helps providers assess whether it aligns with typical email-sending patterns, potentially resulting in account blocking.

3. Recipients Marking Emails as Spam

If cold emails are irrelevant, poorly personalized, or deemed promotional, recipients may mark them as spam. High spam complaint rates negatively impact sender reputation, and exceeding a certain threshold may lead to account blocking by email service providers.

4. Sending to Unverified Lists

Sending cold emails to unverified lists can result in a high email bounce rate, indicating that emails fail to reach the intended recipients. If the bounce rate increases significantly, email service providers may interpret it as potential spamming or poor list management, potentially leading to account blocking.

5. Exceeding Daily Email Quota

Email service providers impose daily email sending limits to prevent spam. Consistently exceeding these limits raises suspicions of spamming or unauthorized email activity. Frequent violations of daily email-sending quotas may lead to email account blocking.

6. Using Spam-Triggering Words

Email service providers utilize machine learning and artificial intelligence to analyze email content and identify potential spam. Emails containing spam-triggering words like "DEAL," "OFFER," or "FREE" may be flagged as potential spam, impacting deliverability and increasing the risk of account blocking.

7. Choosing the Right Email Service Provider

The choice of an email service provider significantly influences email deliverability and account security. Opting for an unreliable provider may negatively impact sender reputation and increase the likelihood of account blocking. Selecting a reputable and compliant provider is essential to avoid such issues.

Best Practices for Successful Cold Email Outreach Without Getting Banned

Cold email outreach can be a powerful strategy for business growth if executed correctly. However, to ensure success and avoid being banned, it is crucial to follow best practices. Let’s discuss five key practices that can help you send cold emails without getting banned.

1. Use a Reputable Email Service Provider (ESP)

Choosing a reputable ESP is the foundation of successful cold email outreach. Reputable ESPs employ advanced algorithms to detect spam and phishing emails, ensuring compliance with email laws and regulations. By using a reputable ESP, you benefit from their expertise in identifying whether your emails might be flagged as spam. Additionally, a reputable ESP helps establish trust with recipients' ESPs, enhancing your sender authenticity.

2. Authenticate Your Emails

Email authentication is a critical aspect of email deliverability. Implement SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting, and Conformance) records to validate the legitimacy of your emails. SPF ensures the sending server is authorized, DKIM adds a digital signature for email integrity, and DMARC provides an extra layer of authentication and reporting. These protocols enhance your credibility with ESPs, reducing the likelihood of your cold emails being marked as spam.

3. Warm Up Your Email Account

Sudden increases in email sending volume, especially with a new email account, can trigger spam filters and lead to emails being routed to the spam folder. To mitigate this risk, warm up your email account gradually by starting with a small number of emails per day and increasing the volume over time. Sending emails to already engaged contacts before launching your cold email campaign signals to ESPs that your account is legitimate and trustworthy. This approach establishes a positive sender reputation and improves the deliverability of your cold emails.

4. Create a Hyper-Targeted Prospect List

Generic, mass cold emails often yield poor results and increase the risk of being marked as spam. Instead, invest time in research to create a hyper-targeted prospect list. Develop ideal customer profiles to understand your prospects' needs, interests, and pain points. This information enables better personalization of your cold emails, leading to higher engagement rates and reducing the likelihood of being flagged as spam.

5. Verify Email Addresses Before Sending

Before launching your cold email campaign, take the crucial step of verifying email addresses on your prospect list. Sending emails to invalid or inactive addresses increases the bounce rate, negatively impacting your sender's reputation and email deliverability. Email verification ensures that your emails reach the intended recipients' inboxes, eliminating the risk of bounced emails and enhancing the overall performance of your cold email outreach campaign.

6. Personalize Your Emails

Personalization is key to successful cold email outreach. Take the time to understand your recipients and tailor your emails accordingly. Address them by their names, mention specific details about their interests or industry, and convey genuine interest in helping them. This personal touch establishes a connection, builds trust, and reduces the likelihood of your email account being blocked.

Utilizing tools like Smartlead can streamline and scale the personalization process, ensuring each prospect receives a tailored message.

7. Avoid Spam-Triggering Words

Certain words and phrases are commonly associated with spam and can trigger spam filters. Words like "Free," "Guaranteed," "Urgent," "Deal," and "Discount" should be avoided. Instead, use clear and professional language that conveys value and relevance. By steering clear of spam-triggering words, you enhance the chances of your emails bypassing spam filters and improve campaign performance.

8. Limit the Number of Links

Excessive links in cold emails can raise suspicions among recipients and trigger spam alerts. To maintain legitimacy and protect your email deliverability, limit the number of links in your emails. Focus on providing valuable content and direct prospects to a single, relevant link. This not only ensures inbox delivery but also enhances the overall user experience.

9. Keep Email Sending Volume Low

To optimize email deliverability and reduce the risk of being flagged as spam, it's advisable to keep your cold email sending volume low. Aim for under 50 emails per day per email account. While many Email Service Providers (ESPs) may have higher sending limits, keeping the volume low helps maintain sender reputation and ensures that emails reach the intended recipients' inboxes. If outreach needs exceed this limit, consider using multiple email accounts.

10. Maintain Proper Text-to-HTML Ratio

Balancing the text-to-HTML ratio is crucial to avoiding spam filters. Excessive HTML code compared to text content can raise suspicions. Strive for a predominantly text-based email, incorporating HTML sparingly for essential formatting or visual enhancements. This practice reduces the likelihood of triggering spam filters and enhances trust from ESPs, increasing the chances of successful email delivery.

11. Include an Unsubscribe Link

One crucial practice to prevent email account blocks is to include an unsubscribe link in your cold emails. This feature allows recipients to easily opt out if they are not interested in receiving further emails. Not only does this show respect for the recipient's preferences, but it also aligns with legal requirements.

Respecting opt-out requests is not only beneficial for maintaining a positive sender reputation but is also a legal obligation. Ignoring opt-out requests can lead to increased spam complaints, which may result in potential email account blocks. Therefore, make sure to include a prominent and easy-to-find unsubscribe link in your cold emails.

12. Monitor Deliverability and Track Key Metrics

Monitoring deliverability is crucial to the success of your cold email outreach campaign. Keep a close eye on your email bounce rate, with the ideal rate being 2% or less. If you experience two or fewer bounces out of 100 cold emails sent, your email deliverability is not significantly impacted. However, a bounce rate higher than 2% signals a need to verify the email addresses on your prospect list before sending additional emails.

In addition to monitoring deliverability, track key metrics such as open rates, click-through rates, reply rates, and spam complaints. Low open rates indicate a need for improvement in your subject line, email content, and overall sender reputation. Analyzing these metrics allows you to identify areas for enhancement and refine your cold email strategy for better engagement and success.


Cold emails are a great way to reach potential customers, but can be challenging. To ensure your emails reach your prospects without getting blocked, it’s essential to understand the rules, regulations & best practices regarding cold emails in your country. Once you know the laws well, you can start building a list of prospects to send emails to.

When sending cold emails, keeping your emails compliant with anti-spam laws is essential. An email verification service can help ensure your emails reach the intended recipient. 

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Author’s Details

Sattwik Das

Sattwik is a Digital Marketing professional at Smartlead. He is a dedicated content writer who focuses on juggling words to bring out meaningful content. He is experienced in well-researched and SEO-optimized content creation, content editing, and copywriting for various businesses throughout the globe. His expertise in SEO, SMM, and SMO with a touch of creativity helps businesses grow and maximize their credibility and sales.


Edited by:

Sattwik Das


Frequently asked questions

General Questions

What is Smartlead's cold email outreach software?

Email automation FAQs- Smartlead

Smartlead's cold email outreach tool helps businesses scale their outreach efforts seamlessly. With unlimited mailboxes, fully automated email warmup functionality, a multi-channel infrastructure, and a user-friendly unibox, it empowers users to manage their entire revenue cycle in one place. Whether you're looking to streamline cold email campaigns with automated email warmups, personalization fields, automated mailbox rotation, easy integrations, and spintax, improve productivity, or enhance scalability with subsequences based on lead’s intentions, automated replies, and full white-label experience, our cold email tool implifies it in a single solution.

How does the "unlimited mailboxes" feature benefit me?

Email automation FAQs- Smartlead

Our "unlimited mailboxes" feature allows you to expand your email communications without restrictions imposed by a mailbox limit. This means you won't be constrained by artificial caps on the number of mailboxes you can connect and use. This feature makes Smartlead the best cold email software and empowers you to reach a wider audience, engage with more potential customers, and manage diverse email campaigns effectively.

What do you mean by "unibox to handle your entire revenue cycle"?

Email automation FAQs- Smartlead

The "unibox" is one of the unique features of Smartlead cold email outreach tool, and it's a game-changer when it comes to managing your revenue cycle. The master inbox or the unibox consolidates all your outreach channels, responses, sales follow-ups, and conversions into one centralized, user-friendly mailbox.

With the "unibox," you gain the ability to:
1. Focus on closing deals: You can now say goodbye to the hassle of logging into multiple mailboxes to search for replies. The "unibox" streamlines your sales communication, allowing you to focus on what matters most—closing deals.

2. Centralized lead management: All your leads are managed from one central location, simplifying lead tracking and response management. This ensures you take advantage of every opportunity and efficiently engage with your prospects.

3. Maintain context: The "unibox" provides a 360-degree view of all your customer messages, allowing you to maintain context and deliver more personalized and effective responses.

How does Smartlead ensure my emails don't land in the spam folder?

Email automation FAQs- Smartlead

Smartlead, the best cold email marketing tool, ensures your emails reach the intended recipients' primary inbox rather than the spam folder. 

Here's how it works:
1. Our "unlimited warmups" feature is designed to build and maintain a healthy sending reputation for your cold email outreach. Instead of sending a large volume of emails all at once, which can trigger spam filters, we gradually ramp up your sending volume. This gradual approach, combined with positive email interactions, helps boost your email deliverability rates.

2. We deploy high-deliverability IP servers specific to each campaign. 

3. The ‘Warmup’ feature replicates humanized email sending patterns, spintax, and smart replies.
4. By establishing a positive sender reputation and gradually increasing the number of sent emails, Smartlead minimizes the risk of your emails being flagged as spam. This way, you can be confident that your messages will consistently land in the primary inbox, increasing the likelihood of engagement and successful communication with your recipients.

Can I integrate Smartlead with other tools I'm using?

Email automation FAQs- Smartlead

Certainly, Smartlead is designed for seamless integration with a wide range of tools and platforms. Smartlead offers integration with HubSpot, Salesforce, Pipedrive, Clay, Listkit, and more. You can leverage webhooks and APIs to integrate the tools you use. Try Now!

Email automation FAQs- Smartlead

What type of businesses sees the most success with Smartlead?

No, there are no limitations on the number of channels you can utilize with Smartlead. Our multi-channel infrastructure is designed to be limitless, allowing you to reach potential customers through multiple avenues without constraints.

This flexibility empowers you to diversify your cold email outreach efforts, connect with your audience through various communication channels, and increase your chances of conversion. Whether email, social media, SMS, or other communication methods, Smartlead's multi-channel capabilities ensure you can choose the channels that best align with your outreach strategy and business goals. This way, you can engage with your prospects effectively and maximize the impact of your email outreach.

Email automation FAQs- Smartlead

Do you provide me with lead sources?

Smartlead distinguishes itself from other cold email outreach software by focusing on limitless scalability and seamless integration. While many similar tools restrict your outreach capabilities, Smartlead offers a different approach.

Here's what makes us uniquely the best cold email software:

1. Unlimited Mailboxes: In contrast to platforms that limit mailbox usage, Smartlead provides unlimited mailboxes. This means you can expand your outreach without any arbitrary constraints.

2. Unique IP Servers: Smartlead offers unique IP servers for every campaign it sends out. 

3. Sender Reputation Protection: Smartlead protects your sender reputation by auto-moving emails from spam folders to the primary inbox. This tool uses unique identifiers to cloak all warmup emails from being recognized by automation parsers. 

4. Automated Warmup: Smartlead’s warmup functionality enhances your sender reputation and improves email deliverability by maintaining humanized email sending patterns and ramping up the sending volume. 

5. Multi-Channel Emphasis: Smartlead places a strong emphasis on multi-channel outreach. You can reach your prospects where they are with the LinkedIn outreach feature.   With Smartlead’s cold email automation software, you're always one step ahead in your outreach efforts, enjoying the freedom to scale your initiatives and seamlessly integrate with other tools—all while maintaining a focus on maximizing the impact of your outreach.

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How secure is my data with Smartlead?

Ensuring the security of your data is Smartlead's utmost priority. We implement robust encryption methods and stringent security measures to guarantee the continuous protection of your information. Your data's safety is paramount to us, and we are always dedicated to upholding the highest standards of security.

How can I get started with Smartlead?

Email automation FAQs- Smartlead

Getting started with Smartlead is straightforward! Just head over to our sign-up page and follow our easy step-by-step guide. If you ever have any questions or need assistance, our round-the-clock support team is ready to help, standing by to provide you with any assistance you may require. Sign Up Now!

How can I reach the Smartlead team?

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We're here to assist you! You can easily get in touch with our dedicated support team on chat. We strive to provide a response within 24 hours to address any inquiries or concerns you may have.

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