Why do my cold emails go to spam and how can I fix it?

Summary

Cold emails often end up in spam due to a confluence of factors related to relevance, authentication, sender reputation, and technical configuration. Unsolicited emails are inherently viewed with suspicion, and if the content is generic or irrelevant to the recipient, it increases the likelihood of being marked as spam. A lack of proper email authentication (SPF, DKIM, DMARC) makes it difficult for email providers to verify the sender's identity, leading to deliverability issues. Building and maintaining a positive sender reputation is essential, which involves sending wanted content, managing sending volumes, and keeping complaint rates low. Additionally, avoiding spam trigger words, cleaning email lists, providing easy unsubscribe options, and adhering to sending limits all contribute to improved deliverability.

Key findings

  • Relevance & Targeting: Irrelevant or poorly targeted content significantly increases the chances of emails being marked as spam.
  • Unsolicited Nature: Sending unsolicited emails inherently increases the risk of being flagged as spam.
  • Email Authentication: Proper email authentication (SPF, DKIM, DMARC) is crucial for verifying sender identity and improving deliverability.
  • Sender Reputation: A positive sender reputation, built on engagement and low complaint rates, is essential for inbox placement.
  • Unsubscribe Accessibility: Making it difficult to unsubscribe leads to more spam complaints and poorer deliverability.
  • Sending Volume & Limits: Exceeding sending limits and sudden spikes in volume can trigger spam filters.
  • Technical Configuration: Clean HTML, avoiding URL shorteners, and proper domain setup are important for technical deliverability.

Key considerations

  • Improve Audience Targeting: Thoroughly research and target your audience to ensure relevance and engagement.
  • Implement Email Authentication: Configure SPF, DKIM, and DMARC records for your domain to verify your sending server's identity.
  • Monitor Sender Reputation: Regularly monitor your sender reputation, complaint rates, and engagement metrics.
  • Ensure Easy Unsubscribes: Provide a clear and easy-to-use unsubscribe option in every email.
  • Manage Sending Volume: Avoid sudden spikes in sending volume, and gradually warm up new IPs or domains.
  • Optimize Email Content: Avoid spam trigger words, use clean HTML, and test your emails before sending.
  • Maintain List Hygiene: Regularly clean your email list by removing inactive subscribers and those who haven't opted in.

What email marketers say
16Marketer opinions

Cold emails often land in the spam folder due to various factors, including being unsolicited, lacking personalization, and not adhering to best practices. Email service providers flag emails as spam when they lack proper authentication (SPF, DKIM, DMARC), contain spam trigger words, or are sent to unengaged recipients. Senders should prioritize building a good sender reputation by sending relevant content, respecting unsubscribe requests, and gradually increasing sending volume. Ensuring emails are personalized, valuable, and offer an easy way to opt-out are crucial for inbox placement. Moreover, technical aspects like clean HTML, avoiding URL shorteners, and maintaining a clean email list significantly impact deliverability.

Key opinions

  • Unsolicited Nature: Unsolicited emails are commonly marked as spam by both email providers and recipients.
  • Authentication: Lack of proper email authentication (SPF, DKIM, DMARC) is a primary reason for emails going to spam.
  • Engagement: Low engagement (e.g., low open rates, high complaint rates) negatively impacts sender reputation and deliverability.
  • Personalization: Generic, non-personalized emails are more likely to be flagged as spam.
  • Unsubscribe Option: The absence of a clear and easy-to-use unsubscribe option leads to higher spam complaints.
  • Content: Spam trigger words and poor HTML code can cause emails to be filtered.
  • Sending Volume: Sudden increases in sending volume can trigger spam filters, especially for new IPs/domains.

Key considerations

  • Email Authentication Setup: Implement SPF, DKIM, and DMARC records to verify your sending server's identity.
  • List Hygiene: Regularly clean your email list by removing inactive subscribers and those who haven't opted in.
  • Personalization & Relevance: Tailor email content to each recipient's needs and interests to increase engagement.
  • Unsubscribe Process: Make it easy for recipients to unsubscribe from your emails.
  • Content Optimization: Avoid using spam trigger words, clean your HTML code, and test your emails before sending.
  • Sender Reputation Monitoring: Monitor your sender reputation and IP address for blacklisting.
  • IP Warm-up: Gradually increase your sending volume when using a new IP address.
Marketer view

Marketer from Email Geeks shares that unsolicited email is typically regarded as spam and is often flagged by major email providers.

July 2023 - Email Geeks
Marketer view

Email marketer from Woodpecker.co Blog highlights the importance of personalization, relevance, and respecting unsubscribe requests in cold email campaigns to maintain a good sender reputation and avoid spam filters.

May 2022 - Woodpecker.co Blog
Marketer view

Email marketer from Reddit says ensure the email is actually personalized and relevant to the recipient's needs. Generic emails are often flagged as spam. Also, double-check your sending IP address isn't blacklisted.

November 2021 - Reddit
Marketer view

Email marketer from Sendinblue Blog suggests warming up your IP address, segmenting your email list, and engaging subscribers with valuable content to improve deliverability and avoid the spam folder.

June 2024 - Sendinblue Blog
Marketer view

Marketer from Email Geeks shares that receivers often mark unsolicited emails as spam, regardless of unsubscribe links, due to a lack of trust or interest in the sender. They might avoid clicking on links in such emails.

March 2021 - Email Geeks
Marketer view

Email marketer from Reply.io Blog advises starting with a well-researched and targeted list, crafting personalized email sequences with clear value propositions, and testing different approaches to find what resonates best with your audience.

June 2023 - Reply.io Blog
Marketer view

Marketer from Email Geeks explains that the nature of the email content and the recipient data are problematic in cold email scenarios. Temporary fixes may exist, but a better approach involves examining and refining the data and content to maintain a sustainable program. The process is essentially a continuous cycle of tweaking, testing, and repeating because the email filter algorithms will generally prevail.

December 2023 - Email Geeks
Marketer view

Marketer from Email Geeks refers to a Litmus study that indicates 50% of people mark emails as spam due to the absence of a clear or easily accessible unsubscribe option. Therefore, including an unsubscribe link is crucial.

May 2021 - Email Geeks
Marketer view

Marketer from Email Geeks says an email is spam if it's equally applicable to many recipients and the recipient hasn't explicitly granted permission to receive it. One-to-one email is only legitimate way to cold email without it being spam.

March 2023 - Email Geeks
Marketer view

Email marketer from Litmus Blog explains how email authentication methods like SPF, DKIM, and DMARC work to verify the sender's identity and protect against spoofing, improving email deliverability.

March 2022 - Litmus Blog
Marketer view

Email marketer from Warrior Forum suggests gradually increasing sending volume to warm up the IP and domain reputation. Avoid sending large volumes of emails too quickly, which can trigger spam filters.

February 2025 - Warrior Forum
Marketer view

Email marketer from Mailchimp Resources recommends using a recognizable 'From' name, cleaning your audience regularly, and testing your email content with tools like Mailchimp's Inbox Preview to see how it appears in different email clients. Authenticating your domain is also crucial.

June 2021 - Mailchimp Resources
Marketer view

Marketer from Email Geeks recommends limiting the number of emails sent per day, restricting the number of emails sent to a single domain, avoiding attachments, and including an unsubscribe link in cold emails.

July 2023 - Email Geeks
Marketer view

Email marketer from Neil Patel Blog shares several tips for avoiding spam filters, including avoiding spam trigger words, authenticating your email (SPF, DKIM, DMARC), maintaining a clean email list, and providing an easy way to unsubscribe.

April 2022 - Neil Patel Blog
Marketer view

Email marketer from Gmass Blog shares that avoiding URL shorteners and ensuring your HTML is clean, can help to improve deliverability. It's also important to monitor your sender reputation regularly.

September 2024 - Gmass Blog
Marketer view

Email marketer from Hubspot Blog advises cleaning your contact lists and removing inactive subscribers, as well as using double opt-in and making sure that your email content is valuable and relevant to your subscribers.

July 2024 - Hubspot Blog

What the experts say
4Expert opinions

Cold emails frequently end up in spam due to irrelevance, poor audience targeting, lack of authentication, and a poor sender reputation. If recipients consistently mark emails as unwanted, or emails are sent to a poorly targeted audience, it signals to email providers that the emails are spam. Establishing credibility with mailbox providers through proper email authentication (SPF, DKIM, DMARC) is critical for avoiding the spam folder. Building and maintaining a positive sender reputation by sending relevant content, managing sending volume, and keeping complaint rates low is also crucial.

Key opinions

  • Irrelevance & Targeting: Irrelevant content and poor audience targeting are major factors in cold emails being marked as spam.
  • Recipient Signals: When recipients mark emails as unwanted, it strongly contributes to emails being flagged as spam.
  • Authentication: Lack of email authentication (SPF, DKIM, DMARC) significantly reduces credibility with mailbox providers.
  • Sender Reputation: A poor sender reputation, influenced by sending volume and complaint rates, negatively affects inbox placement.

Key considerations

  • Audience Alignment: Ensure emails are relevant to the recipient's interests and needs by thoroughly researching and targeting your audience.
  • Email Authentication: Implement SPF, DKIM, and DMARC to verify the sender's identity and legitimacy.
  • Sender Reputation Management: Monitor sending volume, complaint rates, and engagement metrics to maintain a positive sender reputation.
  • Avoid Frustrating Recipients: Avoid sending follow-ups that can be perceived as annoying or spammy.
Expert view

Expert from Email Geeks explains that unsolicited emails often land in spam folders. The content might be irrelevant to the recipient. Sending emails to the wrong audience increases the likelihood of being marked as spam.

September 2021 - Email Geeks
Expert view

Expert from Email Geeks explains that if recipients mark emails as unwanted, it is a sign they don't want the email. Likely the emails are being sent to the totally wrong audience. Also being cute like "oops, just one more try to see if you forgot to reply" just frustrates people.

September 2024 - Email Geeks
Expert view

Expert from SpamResource explains that proper email authentication (SPF, DKIM, DMARC) is critical for establishing credibility with mailbox providers. Lack of authentication is a common reason for emails ending up in the spam folder, as it makes it difficult for providers to verify the sender's identity and legitimacy.

August 2021 - SpamResource
Expert view

Expert from Word to the Wise shares that building and maintaining a good sender reputation is crucial for inbox placement. Factors like sending volume, complaint rates, and engagement metrics all influence how mailbox providers view your emails. Consistently sending relevant, wanted content to engaged subscribers is key to building a positive reputation.

March 2023 - Word to the Wise

What the documentation says
5Technical articles

Email deliverability issues, particularly cold emails landing in spam, stem from a lack of proper authentication and adherence to established sending practices. Google Postmaster Tools emphasizes the importance of SPF, DKIM, and DMARC for authentication, maintaining low spam rates, and avoiding abrupt changes in email volume. Microsoft 365 documentation highlights sending limits and best practices to prevent being flagged as a spammer. Technical documentation from RFC (SPF), DMARC.org, and DKIM.org collectively outline the mechanisms for verifying the sender's identity and ensuring message integrity, which are crucial for avoiding spam filters.

Key findings

  • Authentication: Proper email authentication (SPF, DKIM, DMARC) is essential for avoiding spam filters.
  • Google Requirements: Google requires senders to keep spam rates below 0.10% and avoid sudden spikes in email volume.
  • Sending Limits: Exceeding sending limits set by providers like Microsoft can lead to emails being marked as spam.
  • Spoofing Prevention: SPF helps prevent email address spoofing by verifying authorized sending servers.
  • Message Integrity: DKIM provides a way to verify that a message was sent by the authorized domain owner and hasn't been tampered with.
  • Policy Enforcement: DMARC allows domain owners to specify how email receivers should handle messages that fail authentication.

Key considerations

  • Implement SPF, DKIM, DMARC: Configure SPF, DKIM, and DMARC records for your domain to authenticate your email.
  • Monitor Google Postmaster Tools: Regularly check Google Postmaster Tools to monitor spam rates and sending reputation.
  • Adhere to Sending Limits: Stay within the sending limits set by email providers like Microsoft.
  • Review Authentication Failures: Use DMARC reporting to identify and address any authentication failures.
  • Gradual Volume Increases: Avoid sending large volumes of email too quickly, especially from new IPs or domains.
Technical article

Documentation from RFC defines the Sender Policy Framework (SPF) and how it helps prevent email address spoofing. Implementing SPF records in your domain's DNS settings tells receiving mail servers which mail servers are authorized to send email on behalf of your domain.

April 2023 - RFC 4408
Technical article

Documentation from Google Postmaster Tools explains that senders should authenticate their email using SPF, DKIM, and DMARC. Also, keep spam rates reported in Postmaster Tools below 0.10% and avoid sudden spikes in email volume.

November 2022 - Google Postmaster Tools
Technical article

Documentation from DKIM.org explains that DomainKeys Identified Mail (DKIM) enables email senders to cryptographically sign their email messages, which email receivers can then verify using the sender's public key published in DNS. This confirms that the message was sent by the authorized domain owner.

October 2021 - DKIM.org
Technical article

Documentation from DMARC.org describes DMARC and its use with SPF and DKIM to provide email authentication. DMARC allows domain owners to specify how they want email receivers to handle messages that fail authentication checks, and it provides reporting mechanisms for monitoring email authentication results.

April 2021 - DMARC.org
Technical article

Documentation from Microsoft 365 Documentation outlines sending limits and best practices for avoiding being marked as a spammer. Staying within these limits is important for avoiding spam filters.

December 2022 - Microsoft 365 Documentation