Summary
Non-subscribers receiving marketing emails and submitting unsubscribe requests is a multifaceted issue stemming from various technical, procedural, and user-related factors. These include direct sending, forwarding/wrong lists, DMARC variances among MBPs, data breaches/purchased lists, form stuffing/scraping, typos in signups, poor list hygiene/outdated data, unclear partner signup forms, system misconfigurations, compromised accounts, spam policy violations, incorrect address harvesting, and the absence of confirmation messages. These issues result in emails reaching unintended recipients who then request to be unsubscribed.
Key findings
- Sending Source: Unsubscribe requests coinciding with sends suggest the marketing efforts are the cause
- List Errors: Inaccurate or incorrect lists lead to emails reaching non-subscribers through forwarding, typos, or harvesting errors.
- DMARC Inconsistencies: Mailbox providers may not uniformly enforce DMARC policies.
- Data Acquisition Issues: Compromised data, purchased lists, and form abuse contribute to invalid email addresses.
- Technical Problems: Improperly configured systems, compromised accounts, and spam policy violations can cause unintended delivery.
- Consent and Transparency: Lack of clear consent on partner forms and absence of confirmation mechanisms result in unintended subscriptions.
Key considerations
- Review Sending Practices: Assess and refine current email sending practices and list management.
- List Accuracy: Implement validation, hygiene and verification processes.
- DMARC Monitoring: Monitor DMARC records.
- Data Security: Protect against and data breaches.
- Technical Safeguards: Secure email and prevent policy violations.
- Consent Transparency: Ensuring Clear Consent through various processes.
What email marketers say
8 marketer opinions
Non-subscribers receiving marketing emails and submitting unsubscribe requests can stem from several issues. These include: Mailbox Providers (MBPs) handling DMARC differently, data breaches, purchased lists, form stuffing/scraping adding unintended emails, email forwarding, list bombs, overlapping lists, typos in sign-up forms, poor list hygiene, outdated lists, and unclear partner signup forms. All of these contribute to sending emails to unintended recipients, resulting in unsubscribe requests from individuals who never opted in.
Key opinions
- DMARC Variance: Mailbox Providers may not uniformly enforce DMARC, leading to inconsistent email authentication results.
- Data Breaches: Illegally obtained email addresses from data breaches or purchased lists are a common source of sending to non-subscribers.
- Form Abuse: Form stuffing or scraping by bots adds unintended emails to lists without consent.
- Forwarding & Bombs: Email forwarding rules and list bombs can cause non-subscribers to receive emails inadvertently.
- List Errors: Typos in signup forms result in emails sent to unintended, albeit similar, addresses.
- List Hygiene: Poor list hygiene, outdated lists, and unclear partner signups contribute to sending to those who didn't opt-in.
Key considerations
- DMARC Monitoring: Monitor DMARC reports to identify authentication issues and potential spoofing.
- Form Security: Implement CAPTCHA and other measures to prevent form stuffing and scraping.
- List Segmentation: Segment and manage lists carefully to avoid overlap and ensure proper targeting.
- Data Validation: Implement email validation and address verification to reduce typos and invalid entries.
- List Hygiene Practices: Regularly clean and update email lists to remove inactive or unengaged subscribers.
- Partner Transparency: Ensure signup forms on partner sites clearly communicate subscription details and consent requirements.
Marketer view
Email marketer from ActiveCampaign explains that signup forms on partner sites sometimes don't make it clear you are signing up for multiple lists. People may not realise they are subscribing to *your* marketing emails.
25 Sep 2023 - ActiveCampaign
Marketer view
Marketer from Email Geeks notes that not all Mailbox Providers (MBPs) use/honor DMARC in the same way and asks if there is a correlation with who is using the form.
15 Aug 2024 - Email Geeks
What the experts say
6 expert opinions
When non-subscribers receive marketing emails and submit unsubscribe requests, it could mean a message was likely sent by the sender directly. There are also two possible causes: email forwarding or the wrong list being used for mailing. Investigating requires obtaining a copy of the problematic email, ideally with full headers, or using tracking links, unsubscribe links, or personalization if headers are not available. Incorrectly configured address harvesting can lead to emails sent to role accounts or similar addresses. Finally, confirmation messages help users confirm their intention which helps with data quality.
Key opinions
- Coincidental Sending: Unsubscribe requests coinciding with email sends suggests the messages were likely sent by the user.
- Forwarding or Wrong List: Potential causes include email forwarding or using the wrong mailing list.
- Investigation Methods: Obtain the email in question, ideally with full headers, or use tracking links/personalization to identify the recipient.
- Harvesting Errors: Incorrect address harvesting can send emails to role accounts or similar addresses.
- Confirmation Messages: Confirmation messages improve data quality by confirming user intention to receive emails.
Key considerations
- Message Review: If unsubscribe requests align with email sends, carefully review sent messages.
- List Verification: Verify the accuracy and intended use of the mailing list.
- Header Analysis: Obtain and analyze email headers or use available tracking data to determine the recipient.
- Harvesting Configuration: Ensure correct address harvesting configuration to avoid sending to unintended addresses.
- Confirmation Implementation: Use confirmation messages or double opt-in to ensure email addresses are valid and the user desires to receive emails.
Expert view
Expert from Email Geeks suggests that if the unsubscribe requests coincide with email sends, the message complained about is likely one that was sent by Allie.
16 Feb 2022 - Email Geeks
Expert view
Expert from Spamresource explains how confirmation messages help users confirm their intention of getting mail which helps with data quality.
4 Mar 2025 - Spamresource
What the documentation says
3 technical articles
Non-subscribers receiving marketing emails and submitting unsubscribe requests can occur due to improperly configured systems, compromised email accounts used for sending spam, and violation of spam policies which leads to deliverability issues. These technical and security-related factors result in emails reaching unintended recipients, prompting unsubscribe requests from those who never subscribed.
Key findings
- System Misconfiguration: Improperly configured systems can lead to sending unsolicited emails to unintended recipients.
- Account Compromise: Compromised email accounts are often used by attackers to send spam, reaching non-subscribers.
- Policy Violations: Violating spam policies can result in deliverability issues, causing emails to reach unintended recipients.
Key considerations
- System Security: Regularly review and secure email systems to prevent misconfiguration and unauthorized access.
- Account Protection: Implement strong password policies and multi-factor authentication to protect email accounts from compromise.
- Compliance Monitoring: Adhere to spam policies and monitor email practices to avoid deliverability penalties.
Technical article
Documentation from RFC Editor details issues of unsolicited email, explaining that improperly configured systems or compromised accounts can lead to sending email to unintended recipients.
13 Jan 2022 - RFC Editor
Technical article
Documentation from Microsoft explains that if email accounts are compromised, attackers can use them to send out spam, leading to emails being sent to people who never subscribed.
21 Jun 2022 - Microsoft
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