How does content filtering affect political emails, and what data is shared with Google in sender pilot programs?
Matthew Whittaker
Co-founder & CTO, Suped
Published 5 Jul 2025
Updated 16 Aug 2025
10 min read
Email deliverability for political campaigns is a unique challenge, often operating under different rules and heightened scrutiny compared to commercial emails. The stakes are high, as reaching voters can significantly impact election outcomes. However, this sector frequently faces particular content filtering hurdles that can send legitimate messages straight to the spam or junk folder, away from the eyes of their intended audience. It is not just about avoiding general spam triggers, but also navigating the nuanced, often politically charged, landscape of mailbox provider algorithms.
The controversy surrounding political emails and filtering intensified with allegations of bias, particularly impacting fundraising efforts. This led to discussions and pilot programs aimed at providing a clearer path for political messages to reach the inbox. Understanding how these filters work and what data is involved is crucial for anyone involved in political email outreach, especially with major mailbox providers like Gmail.
My goal here is to explain the complexities of content filtering for political emails and shed light on what kind of data is, or isn't, shared when senders participate in specific pilot programs. We will look at how these systems evaluate content and explore the implications for email deliverability.
How content filtering works
Content filtering significantly impacts political emails, often more so than standard commercial communications. Mailbox providers employ sophisticated algorithms to identify and filter unwanted messages, which include those perceived as spam, phishing attempts, or containing malicious content. For political emails, this can be particularly problematic due to the often-heated and partisan language used, which might inadvertently trigger these filters.
Keywords play a major role. Certain phrases or terms, especially those associated with spam or controversial topics, can flag an email. One study, for example, noted that the term "radical left" was frequently flagged by Gmail's filter, illustrating how specific political language can be misconstrued by automated systems. This doesn't necessarily indicate bias, but rather highlights how content filter algorithms can react to patterns of user complaints or engagement associated with certain phrases, regardless of political affiliation.
Beyond explicit keywords, content filtering also considers various other elements. This includes the presence of too many images, specific formatting (like excessive capitalization or exclamation points), and the use of shortened URLs. Email providers also analyze sender reputation, which is influenced by factors like spam complaints, bounce rates, and engagement metrics. If a sender's reputation is poor, even well-crafted content might struggle to reach the inbox. This is why understanding why your emails are going to spam is critical for all senders, political or otherwise.
Mailbox providers often make filtering decisions based on complex assumptions. They try to predict what users want to see and what they consider spam. This involves analyzing a vast amount of data, including user interactions, reported spam, and engagement rates. For example, if a large number of users mark emails from a political campaign as spam, the filtering algorithm learns to treat similar emails from that sender, or even containing similar content, with increased suspicion. This behavioral feedback loop is a key part of why email providers make certain filtering decisions.
Google's political email pilot program
In response to concerns about political emails landing in spam folders, especially from Republican campaigns, Google launched a pilot program. This program, approved by the Federal Election Commission (FEC) in August 2022, aimed to allow authorized candidate committees and political party committees to bypass spam filters and land in the primary inbox. The FEC's advisory opinion provided the legal framework for this initiative.
The core idea behind this pilot was to provide a mechanism for campaigns to ensure their emails were delivered, provided they met specific criteria. Participants were required to be U.S. federal candidate committees, committees of national political parties, or congressional campaign committees. This program was designed to offer more clarity and predictability for political senders, moving away from relying solely on algorithmic assessments for deliverability.
For more details on what this program entailed and its requirements, you can refer to our guides on Google's pilot program for political emails and the specifics of the Gmail verified sender program. It's worth noting that the program faced scrutiny and ultimately concluded, with Google stating they would evaluate next steps. However, the discussions around it highlighted broader issues of email deliverability for political content.
Data shared in sender pilot programs
A key concern raised by political groups, such as the Republican National Committee (RNC), was about the data shared with Google through the pilot program. They expressed apprehension about providing additional information to a tech company they accused of bias. However, many email deliverability experts pointed out that much of the data Google would receive was likely data they already collected through their normal email processing, just perhaps in a more structured and official capacity.
When an email is sent to a Gmail address, Google's systems process it for various checks, including spam detection, malware scanning, and policy enforcement. This means they already have access to the email content, sender information (IP address, domain), authentication results (SPF, DKIM, DMARC), and user engagement data (opens, clicks, spam complaints). The pilot program primarily offered a formal channel for authorized political campaigns to submit their information and receive special treatment, rather than exposing entirely new categories of data to the service provider.
For specific details on the pilot program's requirements and data considerations, the Federal Election Commission's Advisory Opinion 2022-14 outlines the legal basis and some operational aspects. It emphasizes that participating campaigns would still need to comply with email best practices and that users would retain the ability to opt-out of receiving these emails or mark them as spam.
The primary intent of this program was not to gather new data, but to allow campaigns to proactively identify themselves and their emails to Gmail. This would help Gmail differentiate legitimate political messages from general spam or phishing attempts, ensuring more reliable delivery. This formal enrollment process provides a layer of trust and identification that traditional content filters might struggle to infer on their own.
Impact and best practices for political senders
The impact of content filtering on political emails can be significant, directly affecting reach and engagement. When emails are consistently routed to the spam folder or a blocklist (also known as a blacklist), campaigns lose the opportunity to communicate critical messages, solicit donations, or mobilize supporters. This is why political emails often end up in spam.
Despite the existence of pilot programs, political senders must adhere to core email deliverability best practices. Relying solely on a bypass program is risky, especially since such programs may be temporary or have strict eligibility criteria. A strong sender reputation built on consistent good practices is the most reliable path to the inbox.
Maintain a clean list: Regularly remove inactive or unengaged subscribers. Avoid purchasing or renting email lists, as these often contain spam traps or invalid addresses that can severely damage your sender reputation and lead to getting your domain on a blacklist.
Ensure proper authentication: Implement SPF, DKIM, and DMARC. These protocols verify your sending identity and significantly reduce the likelihood of your emails being flagged as spam or phishing. Our guide on technical solutions for deliverability can provide more insights.
Monitor engagement: Pay close attention to open rates, click-through rates, and, most importantly, spam complaint rates. Low engagement and high complaints indicate problems that need addressing. Google Postmaster Tools is an excellent resource for this.
Craft engaging content: While political emails can be passionate, avoid excessive use of all caps, exclamation points, and overly aggressive language. Focus on clear, concise messaging that encourages positive interaction. Ensure your emails are mobile-friendly and accessible.
Provide clear unsubscribe options: Make it easy for recipients to opt-out. Hidden or complex unsubscribe processes lead to frustration and, inevitably, spam complaints, which hurt your sender reputation.
By focusing on these fundamental aspects of email deliverability, political campaigns can significantly improve their chances of reaching the inbox, regardless of specific pilot programs or the inherent challenges of political content filtering.
Views from the trenches
Best practices
Always prioritize building a strong sender reputation through consistent positive engagement, as this is the most reliable path to the inbox for political emails.
Segment your email lists based on engagement and political affiliation to tailor content and reduce the likelihood of spam complaints.
Implement strong email authentication protocols like SPF, DKIM, and DMARC to verify your sending identity and build trust with mailbox providers.
Regularly monitor your email deliverability metrics, including open rates, click-through rates, and spam complaint rates, using tools like Google Postmaster Tools.
Ensure your unsubscribe process is straightforward and visible, making it easy for recipients to opt out gracefully and avoid marking your emails as spam.
Common pitfalls
Relying solely on special pilot programs or political exemptions without maintaining general email deliverability best practices.
Using highly aggressive or inflammatory language and excessive formatting (e.g., all caps, too many exclamation points) that can trigger content filters.
Acquiring email lists from third-party sources, which often contain invalid addresses, spam traps, and unengaged users, leading to high bounce and complaint rates.
Failing to monitor engagement and sender reputation metrics, leading to unnoticed deliverability issues that escalate over time.
Neglecting to provide clear and easy unsubscribe options, forcing frustrated recipients to mark emails as spam, which severely damages sender reputation.
Expert tips
Focus on the long-term health of your sending domain and IP. A sustained positive reputation is far more valuable than short-term tricks or perceived loopholes.
Understand that content filters evolve based on user behavior. What worked last cycle might not work this one, so continuous monitoring is essential.
Even in politically charged environments, aim for clear, concise, and value-driven messaging. Overly sensationalized content risks being flagged.
Consider segmenting your content by sensitivity. Less controversial updates can go to a broader audience, while more direct asks might go to highly engaged segments.
Engage in conversations with mailbox providers if you have significant issues. They often have postmaster teams that can provide guidance, although they won't reveal proprietary algorithms.
Expert view
Expert from Email Geeks says Google emphasizes attaching reputation to anything they find significant, suggesting that certain content strings being flagged are more indicative of user spam reporting behavior than inherent bias.
2022-11-04 - Email Geeks
Marketer view
Marketer from Email Geeks says the RNC's concerns about sharing data with Google in the pilot program seemed unfounded, as Google already possesses most of that data through its normal email processing.
2022-11-04 - Email Geeks
Key takeaways
Content filtering remains a critical aspect of email deliverability, especially for political emails that often walk a fine line between compelling advocacy and spam triggers. While programs like Google's pilot aimed to provide a clearer path, the underlying principles of good sender reputation and adherence to email best practices are paramount. The data shared in such programs is generally what mailbox providers already analyze, merely formalized for specific sender categories.
Ultimately, successful political email campaigns, like all others, depend on building and maintaining trust with recipients and mailbox providers. By understanding how content filtering works and what truly impacts deliverability, campaigns can focus on strategies that ensure their messages reach their intended audience effectively.
Gmail.
Gmail's filter, illustrating how specific political language can be misconstrued by automated systems. This doesn't necessarily indicate bias, but rather highlights how content filter algorithms can react to patterns of user complaints or engagement associated with certain phrases, regardless of political affiliation.
Google launched a pilot program. This program, approved by the Federal Election Commission (FEC) in August 2022, aimed to allow authorized candidate committees and political party committees to bypass spam filters and land in the primary inbox. The FEC's advisory opinion provided the legal framework for this initiative.
