Summary
Sending unsolicited marketing emails through other ESPs creates a cascade of problems encompassing technical, legal, and reputational aspects. This practice, often termed 'proxying', involves sending emails to unconsenting recipients via a secondary ESP, offloading the negative repercussions onto that ESP. Key issues include authentication failures (SPF, DKIM, DMARC), tarnished domain reputation with providers like Google and Microsoft, potential IP blocking and blocklist placement, violations of anti-spam laws (GDPR, CAN-SPAM) leading to fines, erosion of user trust and engagement, and long-term damage to brand perception, with the added risk of 'list bombing'. Remediating these issues is costly and time-consuming.
Key findings
- Reputation Damage: Sender and proxied ESP reputations are damaged, potentially leading to blacklisting and deliverability issues.
- Legal Issues: Violates anti-spam laws like GDPR and CAN-SPAM, resulting in potential fines and legal repercussions.
- Authentication Failures: Causes authentication failures (SPF, DKIM, DMARC), negatively impacting deliverability.
- Decreased Engagement: Reduces open rates, click-through rates, and increases unsubscribe rates, hurting email marketing ROI.
- Erosion of Trust: Erodes user trust, diminishing the effectiveness of future legitimate campaigns.
- List Bombing: Increases the risk of list bombing, which adds users to lists without consent.
Key considerations
- Ethical Sending: Prioritize permission-based email marketing to protect sender reputation and user trust.
- Compliance: Ensure all email marketing activities comply with anti-spam laws and regulations.
- Authentication: Implement and maintain strong email authentication protocols (SPF, DKIM, DMARC).
- Reputation Monitoring: Monitor sender domain and IP reputation using tools like Google Postmaster Tools and Microsoft SNDS.
- Policy Adherence: Adhere to the policies of major email providers and anti-spam organizations (e.g., Spamhaus).
- Avoid Proxying: Avoid using secondary ESPs to send unsolicited emails as it is unethical and harmful.
What email marketers say
9 marketer opinions
Sending unsolicited marketing emails through other ESPs presents significant issues. It damages sender reputation, leads to potential blacklisting, and violates anti-spam laws like GDPR and CAN-SPAM. High spam complaint rates affect deliverability across all campaigns. User trust erodes, engagement metrics decline (lower open rates, click-through rates, and higher unsubscribe rates), and email marketing ROI suffers. Remediating the damage can be costly and time-consuming, and the brand's reputation is tarnished, leading to potential long-term damage and loss of customers. Finally it can lead to list bombing.
Key opinions
- Reputation Damage: Sending unsolicited emails severely damages the sender's reputation, potentially leading to blacklisting.
- Legal Violations: Unsolicited emails violate anti-spam laws (GDPR, CAN-SPAM), resulting in fines and legal issues.
- Decreased Engagement: Unsolicited emails reduce engagement metrics (open rates, CTR) and increase unsubscribe rates.
- Erosion of Trust: User trust in the brand is eroded, reducing the likelihood of future engagement.
- List Bombing: Using another ESP can lead to list bombing issues.
Key considerations
- Compliance: Ensure all email marketing practices comply with anti-spam laws and regulations.
- Sender Reputation: Actively monitor and protect sender reputation to maintain email deliverability.
- User Trust: Prioritize building and maintaining user trust through permission-based email marketing practices.
- List Hygiene: Careful consideration is needed to avoid list bombing and being added to lists without permission.
- Cost of Remediation: Be aware that remediating damage caused by unsolicited emails can be expensive and time-consuming.
Marketer view
Email marketer from Quora responds that unsolicited emails lead to lower open rates, click-through rates, and higher unsubscribe rates, ultimately damaging your email marketing ROI.
9 Sep 2021 - Quora
Marketer view
Marketer from Email Geeks asks if the scenario is where an ESP is sending cold emails advertising itself through a different ESP.
29 Jan 2025 - Email Geeks
What the experts say
3 expert opinions
Sending unsolicited marketing emails through other ESPs causes significant issues related to reputation damage and proxying. It involves sending emails to recipients who haven't requested them, offloading the negative reputation impact of spamming onto the competitor ESP. This proxying harms the reputation of the ESP being used without permission, potentially leading to blacklisting and deliverability problems for its legitimate users. Furthermore, it ultimately damages the brand's reputation, leading to negative perceptions from potential customers.
Key opinions
- Reputation Offloading: ESPs send unsolicited emails via other ESPs to avoid damaging their own reputation, offloading it onto the proxied ESP.
- Proxying: Using another ESP to send unsolicited emails is a form of proxying that violates acceptable use policies.
- Reputation Damage to Proxied ESP: The proxied ESP's reputation is harmed, potentially leading to blacklisting and deliverability issues for its users.
- Brand Reputation Damage: The practice ultimately damages the brand reputation of the ESP sending the unsolicited emails.
Key considerations
- Avoid Proxying: Refrain from using other ESPs to send unsolicited emails, as it violates ethical and legal email marketing practices.
- Protect Reputation: Focus on building and maintaining a positive sender reputation through permission-based email marketing.
- Ethical Marketing: Adhere to ethical marketing principles and respect recipient preferences to avoid damaging your brand's image.
- AUP Compliance: Ensure that your email marketing practices are compliant with the Acceptable Use Policy of your ESP.
Expert view
Expert from Email Geeks explains the issue is that someone is sending mail to addresses that haven’t requested it and offloading the reputation hit for spamming onto one of their competitors.
12 Dec 2023 - Email Geeks
Expert view
Expert from Spam Resource explains that using another ESP to send unsolicited emails is a form of proxying and harms the reputation of the proxied ESP, leading to potential blacklisting and deliverability issues for the legitimate users of that ESP.
5 May 2024 - Spam Resource
What the documentation says
4 technical articles
Sending unsolicited marketing emails through other ESPs leads to a multitude of technical and deliverability problems, as outlined by key documentation sources. It causes authentication failures (SPF, DKIM, DMARC), negatively impacts sender domain reputation with major email providers like Google, can result in IP address blocking by Microsoft's email services (Outlook, Hotmail), and potentially leads to blocklist placement with organizations like Spamhaus. These issues significantly degrade deliverability, causing emails to land in spam folders or be blocked entirely.
Key findings
- Authentication Failures: Unsolicited emails sent via other ESPs can cause SPF, DKIM, and DMARC authentication failures for the legitimate sending domain.
- Reputation Damage with Google: Google's Postmaster Tools indicates that sending unsolicited emails negatively impacts sender domain reputation, increasing spam placement.
- IP Blocking by Microsoft: Microsoft SNDS clarifies that unsolicited emails can lead to IP address blocking by Outlook and Hotmail.
- Blocklist Placement: Spamhaus policy prohibits sending cold emails, and using another ESP for this purpose can result in blocklist placement.
Key considerations
- Authentication Protocols: Implement and maintain proper email authentication protocols (SPF, DKIM, DMARC) to prevent deliverability issues.
- Reputation Management: Monitor sender domain and IP reputation with tools like Google Postmaster Tools and Microsoft SNDS.
- Compliance with Policies: Adhere to the policies of major email providers and anti-spam organizations like Spamhaus to avoid penalties.
- Permission-Based Sending: Ensure that all email marketing practices are permission-based to maintain a positive sender reputation and high deliverability.
Technical article
Documentation from Microsoft SNDS clarifies that sending unsolicited emails can lead to IP addresses being blocked by Microsoft's email services (Outlook, Hotmail), severely affecting deliverability to those users.
9 Jan 2024 - Microsoft
Technical article
Documentation from Spamhaus explains if someone uses another ESP for cold emails, this can lead to blocklist placement because that is against Spamhaus' policy.
31 Jan 2023 - Spamhaus
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