What should you do if a client wants to send unsolicited emails?
Michael Ko
Co-founder & CEO, Suped
Published 23 Jun 2025
Updated 15 Aug 2025
6 min read
Dealing with a client who wants to send unsolicited emails (often called spam or junk mail) presents a significant challenge for anyone focused on email deliverability. It's a situation where short-term gains are weighed against long-term damage to sender reputation and overall email program health. While the client might see it as a cost-effective way to reach a large audience, the reality is far more complex and risky.
The immediate impact of sending unwanted emails is often a rapid decline in deliverability, leading to messages landing in spam folders or being outright blocked. Mailbox providers like Google Yahoo and Outlook are increasingly strict, implementing advanced spam filters and requiring senders to adhere to specific sender guidelines. Disregarding these guidelines, or applicable anti-spam laws, can result in serious consequences, including legal penalties and being placed on an email blacklist (or blocklist).
My goal in these situations is always to educate the client about the best practices for sustainable email marketing and guide them towards a strategy that actually yields positive results without jeopardizing their brand or deliverability. It's a delicate balance, especially when they are under pressure to achieve immediate volume goals.
Understanding the problem: Unsolicited email and its consequences
Unsolicited email, commonly known as spam or junk email, refers to any commercial electronic message sent without the recipient's explicit consent. While the definition can vary slightly by region and context, the core principle is a lack of permission. Sending such emails can quickly lead to widespread blocking, as internet service providers (ISPs) and mailbox providers (MBPs) prioritize protecting their users from unwanted communications.
The legal landscape surrounding unsolicited email is complex and varies by country. In the United States, the CAN-SPAM Act sets rules for commercial email, including requirements for identifying the sender, providing a clear unsubscribe mechanism, and avoiding deceptive subject lines. Other regions have even stricter opt-in requirements, such as Canada's Anti-Spam Legislation (CASL) and the European Union's General Data Protection Regulation (GDPR). Violating these laws can result in substantial fines and legal repercussions.
Beyond legal risks, sending unsolicited emails severely damages sender reputation. When recipients mark messages as spam, ignore them, or report them, it sends negative signals to MBPs. This can lead to your sending IP addresses and domains being placed on various blocklists (or blacklists), preventing even legitimate emails from reaching the inbox. Recovering a tarnished sender reputation is a lengthy and difficult process, potentially impacting all email communications, including critical transactional messages. You can learn more about how long it takes to recover domain reputation from our other guides.
Typical bounce errors for unsolicited email
When sending large volumes of unsolicited email, you'll often see specific bounce codes from mailbox providers, indicating that your messages are being rejected or delayed due to suspected spam activity. Understanding these codes is the first step in diagnosing deliverability issues.
Examples of unsolicited email bounce messages
Status: 4.4.2 (bad connection)
Status: 4.4.7 (delivery time expired)
smtp;554 5.1.0 xxx.x.xx.xxx Comcast block for spam. Please see http://postmaster.comcast.net/smtp-error-codes.php#BL000000
smtp;550 5.1.0 <b6dc274423jccj9i2sahv2762ems9a1e74qcjemea2v@bounce.myupgradeportal.com> sender rejected. Refer to Error Codes section at https://www.cox.com/residential/support/email-error-codes.html for more information. AUP#CDRBL
Strategies for managing client expectations
When a client is determined to send unsolicited emails, the key is to shift their perspective from short-term volume to long-term value and sustainable growth. I start by explaining that email is a relationship-building tool, not a blunt instrument for mass outreach. Sending unwanted messages erodes trust, damages brand reputation, and ultimately leads to diminishing returns. It's about showing them the tangible cost of a short-term spam strategy.
I emphasize the importance of permission-based marketing, explaining that obtaining consent (explicit or implied, depending on jurisdiction and context) is foundational to successful email programs. Building an engaged audience, even if smaller initially, leads to higher open rates, click-through rates, and conversions. I provide examples of how this approach can actually drive better return on investment (ROI) by fostering genuine interest and loyalty, rather than generating complaints and blocklist entries. This often involves showing them how cold emails can harm domain reputation if not handled carefully.
The unsolicited approach
Acquisition: Purchased lists, scraped emails, or general prospecting without consent.
Volume focus: Emphasis on sending to as many recipients as possible, as quickly as possible.
Reputation risk: High likelihood of spam complaints, blocklisting, and domain damage.
Legal exposure: Risk of non-compliance with anti-spam laws like CAN-SPAM or GDPR.
Engagement: Typically very low open and click rates, high unsubscribe rates.
Quality focus: Targeting engaged subscribers with relevant content.
Reputation strength: Maintained high sender reputation, strong inbox placement.
Legal compliance: Adherence to all anti-spam and privacy regulations.
Engagement: Higher open and click rates, lower unsubscribe and complaint rates.
Steps to mitigate damage and improve deliverability
Even if a client is resistant to completely abandoning unsolicited email, there are immediate steps to mitigate the damage and improve deliverability as much as possible. These actions aim to clean up the existing process and reduce the negative signals being sent to mailbox providers.
First, thorough list hygiene is critical. This involves consistently purging complaints, promptly unsubscribing hard bounces, and implementing a strict soft bounce policy to avoid sending indefinitely to problematic addresses. Cleaning up the list, removing unengaged subscribers, and ensuring valid email addresses are crucial for improving engagement and reducing negative feedback. You can check out more on how to convince management not to email inactive subscribers.
Secondly, proper email authentication is non-negotiable. Ensuring SPF, DKIM, and DMARC records are correctly implemented helps verify sender legitimacy and prevents spoofing, which can inadvertently damage reputation. Without these, your emails are far more likely to be flagged as spam, regardless of content. This also means paying attention to Outlook's new sender requirements as well.
Core email hygiene practices
Complaint purging: Ensure recipients who complain are immediately removed from future sends.
Hard bounce management: Permanently remove invalid email addresses after a hard bounce.
Soft bounce policy: Establish a clear policy for retrying soft bounces and eventually removing them.
List scrubbing: Regularly clean lists to remove disengaged or old contacts.
Authentication: Implement and maintain SPF, DKIM, and DMARC records properly.
Unsubscribe visibility: Ensure unsubscribe links are prominent and functional.
Navigating difficult client relationships
Navigating a client relationship where the client insists on practices that compromise email deliverability and sender reputation can be incredibly challenging. It's often a situation where I have to balance my professional integrity with the client's immediate, albeit misguided, objectives.
My primary role is to provide expert guidance and recommend strategies that ensure long-term success and inbox placement. This includes clearly communicating the risks associated with unsolicited sending, such as landing on a blocklist (or blacklist), poor engagement, and potential legal issues. I always emphasize that sending to spam is not a sustainable or effective strategy.
Ultimately, while I can offer advice and implement best practices to mitigate immediate issues, I cannot force a client to change their core approach if they are unwilling. In such cases, it becomes a matter of assessing whether the engagement is sustainable and aligned with my professional standards. Sometimes, the most responsible action is to acknowledge that not all clients can be helped if they refuse to adapt to modern email deliverability standards.
Views from the trenches
Best practices
Clearly communicate the long-term impact of unsolicited email on sender reputation and brand image, emphasizing that email is a relationship-building tool.
Educate clients on the legal implications of anti-spam laws like CAN-SPAM and GDPR, highlighting potential fines and penalties for non-compliance.
Implement robust list hygiene practices, including automated complaint purging, bounce handling, and regular scrubbing of inactive or unengaged subscribers.
Ensure all email authentication protocols (SPF, DKIM, DMARC) are correctly configured and monitored to improve sender legitimacy.
Common pitfalls
Attempting to "plead" with mailbox providers (e.g., Google, Yahoo, Outlook) directly to unblock an IP or domain, as this approach is generally ineffective and can sometimes backfire.
Ignoring early warning signs of deliverability issues, such as increasing bounce rates or low engagement, in the hope that they will self-resolve.
Allowing clients to abruptly increase sending volume to unengaged lists, which almost invariably leads to immediate blocklisting and severe reputation damage.
Failing to implement or properly configure email authentication standards, which makes legitimate emails appear suspicious to spam filters.
Expert tips
Pre-qualify clients before engagement to ensure their email marketing goals align with industry best practices and legal compliance, avoiding problematic relationships.
Leverage data and analytics (e.g., complaint rates, bounce rates, spam trap hits) to objectively demonstrate the negative impact of unsolicited sending.
Be prepared to recommend walking away from a client engagement if their practices fundamentally conflict with ethical and effective email deliverability principles.
Advise clients that repairing a damaged sender reputation takes significant time and consistent adherence to best practices, not quick fixes or magic solutions.
Expert view
Expert from Email Geeks says clients cannot plead their case directly with providers, as repairing sender reputation takes time and requires demonstrating improved sending habits, not just negotiation.
2020-11-14 - Email Geeks
Expert view
Expert from Email Geeks says if the term "prospecting" is used to mean sending unsolicited emails, then the client is acting as a spammer, and mailbox providers are justified in blocking their messages.
Google 
Yahoo and 
Outlook are increasingly strict, implementing advanced spam filters and requiring senders to adhere to specific sender guidelines. Disregarding these guidelines, or applicable anti-spam laws, can result in serious consequences, including legal penalties and being placed on an email blacklist (or blocklist).
