How does cold outreach impact domain reputation and deliverability?

Summary

Cold outreach, if not carefully managed, poses significant risks to domain reputation and email deliverability. Sending unsolicited bulk emails, particularly to unengaged recipients or using spam-like tactics, can lead to severe consequences. Key issues include poor list hygiene, lack of personalization, sudden volume spikes, use of multiple subdomains for spam, and failure to warm up new domains/IPs. These practices can damage sender reputation, causing emails to be filtered as spam or blocked entirely. Experts and documentation alike emphasize the importance of proper list hygiene, warming up, personalization, gradual volume increases, compliance with guidelines, and monitoring sender reputation to mitigate risks and maintain deliverability.

Key findings

  • Poor List Hygiene: Sending to unverified, outdated, or purchased email lists results in high bounce rates, spam trap hits, and decreased deliverability.
  • Lack of Personalization: Generic, non-personalized emails are more likely to be marked as spam and have lower engagement rates, impacting deliverability.
  • Sudden Volume Spikes: Abrupt increases in sending volume can trigger spam filters and negatively impact deliverability, especially from new domains/IPs.
  • Spam-like Tactics: Using spam trigger words, misleading subject lines, or failing to provide an unsubscribe option can damage sender reputation.
  • Subdomain Rotation: Using multiple subdomains to send spam can be interpreted as filter evasion and harm domain reputation.
  • Unengaged Recipients: Repeatedly sending to unengaged recipients signals to ISPs that the sender is not sending relevant content, which hurts deliverability.
  • Impact of Filter Bypassing Services: Using services designed to bypass spam filters may result in serious damage to domain reputation and be seen as a clear indicator of spam practices.

Key considerations

  • List Hygiene: Regularly clean your email list by removing invalid, unengaged, and spam trap addresses. Verify email addresses before sending.
  • Warming Up: Gradually warm up new domains and IP addresses by slowly increasing sending volume and engaging in positive interactions.
  • Segmentation & Personalization: Segment your audience based on relevant criteria and personalize your messaging to increase engagement and relevance, avoiding spam triggers.
  • Volume Management: Avoid sudden spikes in sending volume. Gradually increase volume over time to establish a positive sending reputation.
  • Compliance: Comply with email marketing regulations (e.g., GDPR, CAN-SPAM) by providing clear opt-in/opt-out options and respecting subscriber preferences.
  • Sender Authentication: Implement sender authentication protocols (SPF, DKIM, DMARC) to verify your identity and improve deliverability.
  • Monitor Reputation: Monitor your sender reputation using tools like Google Postmaster Tools and adjust your sending practices accordingly.
  • Cousin Domain Strategy: Consider using cousin domains specifically for cold outreach to insulate the primary domain from potential reputational damage.

What email marketers say
10Marketer opinions

Cold outreach, when not executed properly, can significantly harm domain reputation and email deliverability. Common pitfalls include sending too many emails at once, using spam trigger words, emailing irrelevant or outdated contacts, failing to personalize messages, and lacking an easy unsubscribe option. These practices can lead to low engagement, high bounce rates, increased spam complaints, and ultimately, being flagged as a spammer by ISPs. Proper list hygiene, warming up new domains/IPs, segmenting audiences, personalizing messaging, and gradually increasing sending volume are essential for mitigating these risks.

Key opinions

  • Spam Complaints & Low Engagement: High spam complaint rates and low engagement negatively impact sender reputation, leading to deliverability issues.
  • Poor List Hygiene: Sending to unverified, outdated, or purchased email lists results in high bounce rates and spam trap hits, damaging sender reputation.
  • Lack of Personalization: Generic, non-personalized emails are more likely to be marked as spam and have lower engagement rates.
  • Sudden Volume Spikes: Abrupt increases in sending volume can trigger spam filters and negatively impact deliverability.
  • No Unsubscribe Option: Failing to provide an easy and accessible unsubscribe option leads to frustration and increased spam complaints.
  • Spam Trigger Words: Using words and phrases commonly associated with spam can trigger spam filters, negatively impacting deliverability.

Key considerations

  • List Hygiene: Regularly clean your email list by removing invalid, unengaged, and spam trap addresses.
  • Warming Up: Gradually warm up new domains and IP addresses by slowly increasing sending volume and engaging in positive interactions.
  • Segmentation & Personalization: Segment your audience based on relevant criteria and personalize your messaging to increase engagement and relevance.
  • Engagement Monitoring: Monitor email engagement metrics (open rates, click-through rates) and adjust your strategy based on the data.
  • Compliance: Ensure compliance with email marketing regulations (e.g., GDPR, CAN-SPAM) by providing clear opt-in/opt-out options and respecting subscriber preferences.
  • Sender Authentication: Implement sender authentication protocols (SPF, DKIM, DMARC) to verify your identity and improve deliverability.
Marketer view

Email marketer from Reply.io responds that sending cold emails to unverified and outdated lists will drastically hurt your sender reputation. Always verify email addresses, and remove invalid emails from your list.

June 2023 - Reply.io
Marketer view

Email marketer from Quora states that damaging practices include buying email lists, not personalizing messages, not giving an opt-out, and sending too frequently. Each of these significantly impacts deliverability and sender reputation.

June 2022 - Quora
Marketer view

Email marketer from Warrior Forum explains that failing to clean your email list regularly can lead to sending to spam traps, which are email addresses specifically created to identify spammers. Hitting spam traps will severely damage your sender reputation and deliverability.

September 2021 - Warrior Forum
Marketer view

Email marketer from Reddit explains that aggressive cold outreach without proper segmentation and personalization will likely result in low engagement and high spam complaints. This will directly damage your domain reputation and cause future emails to land in the spam folder.

November 2022 - Reddit
Marketer view

Email marketer from Woodpecker.co shares that cold outreach can negatively impact domain reputation if best practices are ignored. Key issues include high bounce rates, low engagement, and spam complaints, all of which damage sender reputation. Proper segmentation, personalized messaging, and careful list hygiene are crucial to mitigating these risks.

May 2022 - Woodpecker.co
Marketer view

Email marketer from Neil Patel explains that cold emailing can hurt your domain reputation if not done correctly. Sending too many emails at once, using spam trigger words, or emailing irrelevant contacts can result in low engagement and increased spam complaints, negatively impacting your sender reputation and deliverability.

April 2022 - Neil Patel
Marketer view

Email marketer from Hunter.io responds that cold outreach significantly impacts email deliverability. Poorly targeted campaigns, lack of personalization, and sending to outdated lists result in low engagement and high bounce rates. ISPs flag such senders as spammers, leading to decreased inbox placement rates.

December 2024 - Hunter.io
Marketer view

Email marketer from Gmass shares some cold email mistakes that will ruin your domain reputation. This includes not verifying email addresses, using a free email domain, and not providing an unsubscribe link. This leads to deliverability issues and makes it difficult for the email to land in the recipients' inbox.

November 2022 - Gmass
Marketer view

Email marketer from Reddit explains that if you don't warm up a new domain or IP address before engaging in cold outreach, you're more likely to be flagged as a spammer. Warming up involves gradually increasing your sending volume and engaging in positive email interactions.

February 2025 - Reddit
Marketer view

Email marketer from Klenty answers that engaging in spam-like activities like sending too many emails at once or sending to outdated lists will damage your sender reputation. It's important to warm up your email address gradually and ensure that you're emailing valid addresses only.

May 2021 - Klenty

What the experts say
7Expert opinions

Cold outreach can significantly harm domain reputation and deliverability if not implemented correctly. Sending spam through multiple subdomains, engaging in unsolicited bulk emailing without proper list hygiene and personalization, using services that bypass filters, sending sudden spikes in email volume, and repeatedly sending to unengaged users are all practices that negatively impact sender reputation. Experts recommend isolating cold outreach to cousin domains and gradually increasing sending volume to mitigate these risks.

Key opinions

  • Subdomain Rotation: Using multiple subdomains to send spam can be seen as filter evasion.
  • Domain Reputation Impact: Sending spam from a subdomain affects the parent domain's reputation.
  • Poor List Hygiene: Poor list hygiene, lack of personalization, and high complaint rates can significantly harm sender reputation.
  • Volume Spikes: Sudden spikes in email volume can negatively impact deliverability.
  • Unengaged Users: Repeatedly sending to unengaged users negatively impacts sender reputation and deliverability.
  • Filter Bypassing Services: Using services to bypass filters can damage your domain's reputation.

Key considerations

  • Cousin Domains: Consider using cousin domains for cold outreach to protect the primary domain's reputation.
  • Gradual Volume Increase: Gradually increase sending volume, especially when starting a new campaign or using a new IP address.
  • List Management: Maintain clean email lists with engaged recipients to avoid being marked as spam.
  • Personalization: Personalize emails to increase engagement and avoid being flagged as spam.
  • Avoid Spam-like Practices: Avoid practices associated with spam, such as sending unsolicited bulk emails and using deceptive subject lines.
Expert view

Expert from Word to the Wise shares that repeatedly sending to unengaged users negatively impacts your reputation. ISPs notice which users interact with your mail and which ones don't. Sending to those who don't interact can cause your mail to be routed to the spam folder.

November 2023 - Word to the Wise
Expert view

Expert from Email Geeks confirms that sending spam from a subdomain will affect the parent domain's reputation.

December 2021 - Email Geeks
Expert view

Expert from Email Geeks explains that using a service like mailivery to bypass filters suggests the organization may damage its reputation if the same domain is used for their spam.

June 2021 - Email Geeks
Expert view

Expert from Email Geeks shares that if an organization is sending spam through multiple subdomains, spam filters might assume they're rotating subdomains for filter evasion. He suggests considering the potential impact on subdomains used for legitimate mail.

January 2023 - Email Geeks
Expert view

Expert from Email Geeks suggests using cousin domains for cold outreach to protect the reputation of the primary domain. She explains that cold outreach can negatively impact reputation and delivery and recommends isolating it on a separate domain.

November 2021 - Email Geeks
Expert view

Expert from Spam Resource explains that a sudden spike in email volume can negatively impact deliverability. ISPs may see a sudden increase in volume as a sign of spam, which can lead to emails being filtered to the spam folder or blocked completely. Gradual increases in sending volume, especially when starting a new campaign or using a new IP address, are crucial for maintaining good deliverability.

June 2024 - Spam Resource
Expert view

Expert from Spam Resource explains that sending unsolicited bulk emails (cold emails) can significantly harm your sender reputation if not done correctly. Poor list hygiene, lack of personalization, and high complaint rates are key factors that can negatively impact your domain's reputation and lead to deliverability issues.

September 2024 - Spam Resource

What the documentation says
4Technical articles

Cold outreach, when not compliant with best practices, can significantly and negatively impact sender reputation and email deliverability, as highlighted by Google, Microsoft, Spamhaus, and Mailchimp. Sending unwanted or unsolicited emails, particularly to unengaged recipients, using misleading subject lines, and neglecting an unsubscribe option can lead to emails being filtered as spam or blocked entirely. Monitoring sender reputation and adhering to best practices for engagement and compliance are crucial for maintaining deliverability.

Key findings

  • Sender Reputation is Key: Sender reputation is a critical factor in determining email deliverability, with poor practices leading to spam filtering or blocking.
  • Unsolicited Emails Damage Reputation: Sending unwanted or unsolicited emails can severely damage your sender reputation.
  • Engagement Impacts Deliverability: Low audience engagement directly impacts deliverability, emphasizing the importance of cleaning unengaged subscribers.
  • Spamhaus Blocklists: Sending spam can result in IP address or domain being listed on Spamhaus blocklists, severely impacting deliverability.

Key considerations

  • Monitor Sender Reputation: Regularly monitor your sender reputation using tools like Google Postmaster Tools.
  • Adhere to Sender Guidelines: Adhere to sender guidelines provided by email providers like Google and Microsoft.
  • Clean Unengaged Subscribers: Regularly clean your email list of unengaged subscribers to improve audience engagement and deliverability.
  • Avoid Spam-like Practices: Avoid spam-like practices such as using misleading subject lines and failing to provide an easy unsubscribe option.
Technical article

Documentation from Spamhaus explains that sending unsolicited bulk emails (spam) can result in your IP address or domain being listed on their blocklists. This can severely impact your email deliverability, as many ISPs and organizations use Spamhaus data to filter out spam. Avoiding spam-like practices and maintaining a clean sending reputation are essential to staying off these lists.

March 2024 - Spamhaus
Technical article

Documentation from Mailchimp details how audience engagement plays a huge role. Low engagement directly impacts deliverability. Mailchimp explains the importance of cleaning out unengaged subscribers. The engagement of the audience on your email list will determine the rating the audience gets, with a poor rating impacting deliverability.

March 2024 - Mailchimp
Technical article

Documentation from Google Postmaster Tools explains that sender reputation is a key factor in determining email deliverability. Sending unwanted or unsolicited emails (spam) can severely damage your reputation, leading to emails being filtered to the spam folder or blocked entirely. Google recommends monitoring your reputation through Postmaster Tools and adhering to their sender guidelines.

November 2021 - Google Postmaster Tools
Technical article

Documentation from Microsoft shares that cold emailing practices directly affect email deliverability. Sending to unengaged recipients, using misleading subject lines, and failing to provide an easy unsubscribe option can lead to negative feedback and decreased deliverability rates. Microsoft recommends following their best practices to maintain a positive sender reputation.

April 2023 - Microsoft