How do Google algorithm updates impact email deliverability and what are the best practices for B2C senders regarding dedicated IPs and sending domains?
Matthew Whittaker
Co-founder & CTO, Suped
Published 4 Aug 2025
Updated 18 Aug 2025
7 min read
Google's algorithms are always changing. These updates can significantly impact how your emails land in recipient inboxes, especially for B2C senders. Many senders have noticed that emails that once landed in the inbox are now being routed to the spam folder. Understanding these shifts is essential for maintaining strong email deliverability.
The core of Google's approach to email filtering revolves around user engagement and sender reputation. This means your sending practices, rather than just technical configurations, play a crucial role. We have observed that Google's guidelines for email senders emphasize the importance of a positive sending history and low spam complaint rates. Ignoring these evolving factors can lead to significant drops in inbox placement.
Google's algorithms and engagement
Google's email filtering prioritizes how recipients interact with your emails. This means that if recipients consistently open, click, and reply to your messages, it signals positive engagement. Conversely, if your emails are frequently deleted without being opened, marked as spam, or ignored, Google's algorithms will interpret this negatively, regardless of your IP address.
This engagement-centric approach extends to both your overall sending domain and individual recipient accounts. We have found that even if your domain has a generally good reputation, low engagement from a specific Google mailbox can lead to messages being filtered to the spam folder for that particular user. This granular filtering means that a sender's most recent email performance heavily influences future deliverability.
The focus on engagement means that traditional IP-based filtering is less prominent for Google. While IP reputation still matters, especially in preventing a domain from being listed on an email blocklist or blacklist, it's not the primary factor for Gmail. The algorithms are dynamic and constantly adapting to differentiate legitimate senders from spammers. Maintaining a clean list and encouraging positive interactions are key.
Dedicated IPs for B2C senders
For B2C senders, the decision between a dedicated IP and a shared IP can be complex. While a dedicated IP gives you full control over your sending reputation, it also means you bear the sole responsibility for it. This can be challenging, particularly during the initial warmup phase or if your sending volume fluctuates significantly. If you're managing a dedicated IP, it's crucial to understand how to maintain dedicated IP reputation.
A common misconception is that simply moving to a dedicated IP will resolve existing spam folder issues. While it might offer a temporary reset of your sending reputation, Google's engagement-based filtering will eventually reconcile your domain's reputation with your new IP. If underlying engagement problems persist, the deliverability issues are likely to return. This is why a dedicated IP isn't always the magic bullet for B2C senders that some providers claim.
We recommend a careful evaluation for B2C senders. If your volume is high and consistent, and you have the resources to manage IP warm-up and monitor your reputation closely, a dedicated IP might be beneficial. However, for many B2C businesses with fluctuating volumes or less consistent sending patterns, a reputable ESP's shared IP pool can offer better stability because the collective sending volume of many users helps maintain a consistent, warm IP. This is especially true for those concerned about how erratic sending impacts deliverability.
Shared IP
Pros: Reputation is pooled with other senders, reducing individual impact.
Reputation can quickly decline with poor sending practices.
Understanding sending domains
Beyond the IP address, your sending domains are critical. It's important to understand the different domains that appear in email headers and their respective roles in authentication and deliverability. Misconfigurations or a lack of alignment can significantly harm your sender reputation and lead to your emails being filtered as spam or added to a blacklist.
We often distinguish between several types of sending domains:
Envelope From (SPF domain/return path): This is the domain used in the SPF check and specifies where bounce messages should be sent. Every sending system (like your ESP) should have its own dedicated domain for this purpose to ensure bounces are handled correctly. Maintaining a clean list and prompt bounce management is critical.
DKIM d=: This identifies the domain that digitally signed the email. For ESPs, this domain should ideally be separate from your main corporate domain to prevent issues if a customer's sending practices negatively impact your primary domain. For marketing purposes, using a subdomain can help segment and build separate reputations for different sending streams, although it's not strictly necessary for deliverability if overall practices are sound.
Visible From (DMARC authenticated domain): This is the domain email recipients see as the sender. Subdomains are not always required here, and we generally advise against them unless there's a specific, practical reason. Many ESPs use subdomains (e.g., e.example.com) and this is perfectly acceptable as long as DMARC authentication is properly configured.
The key is to achieve strong alignment across all these domains. The more consistent your domain alignment, the better email filters can verify that mail genuinely originates from your organization, reducing the risk of it being mistaken for spoofing or phishing attempts. While not all ESPs allow custom Envelope From domains, any competent one should enable you to sign with your own DKIM d= record.
Best practices for B2C senders
Recent changes announced by Google and Yahoo in 2024 highlight the increasing importance of email authentication, low spam rates, and easy unsubscription for bulk senders. For B2C email marketing, these updates mean an even greater emphasis on list hygiene and engagement. Regularly cleaning your email list to remove unengaged subscribers is no longer optional; it's a critical component of maintaining good standing with ISPs. If you're a B2B sender, you should also be mindful of how these updates impact B2B deliverability.
To navigate these changes effectively, B2C senders should focus on building and maintaining a strong sender reputation across both their IP and domain. This involves more than just setting up technical records like SPF, DKIM, and DMARC. It requires a continuous commitment to sending relevant, desired content to engaged recipients. Always be prepared to adapt your sending strategy as Google and other mailbox providers continue to refine their filtering mechanisms to combat unwanted email.
Views from the trenches
Best practices
Monitor your engagement rates closely; low opens and clicks are red flags for Google's filters.
Implement a strict list hygiene policy, removing unengaged subscribers regularly to improve overall sender health.
Ensure your email authentication (SPF, DKIM, DMARC) is correctly configured and aligned across all sending domains.
Prioritize sending relevant and valuable content that encourages positive recipient interaction, not just sending volume.
Common pitfalls
Relying solely on a dedicated IP to fix deliverability problems without addressing engagement issues.
Ignoring Google Postmaster Tools warnings, which provide crucial insights into your domain and IP reputation.
Sending to old, unengaged, or purchased lists, which will quickly trigger spam filters and damage reputation.
Failing to implement an easy and clear unsubscribe process, leading to higher spam complaints.
Expert tips
Google's algorithms are dynamic and heavily engagement-based; adjust your sending strategy accordingly.
Focus on domain reputation more than IP for Google deliverability, especially for B2C traffic.
Your domain's reputation is continuously evaluated; a good sender is only as good as their last email.
Regularly review your sending practices to align with evolving ISP requirements and avoid blocklists.
Expert view
Expert from Email Geeks says Gmail's algorithms are constantly evolving to combat new spam threats, and they are not fixed. Moving to a dedicated IP is unlikely to resolve persistent spam folder problems for B2C mail, and the warm-up process can be difficult.
2022-03-15 - Email Geeks
Marketer view
Marketer from Email Geeks says Google's filtering is very heavily engagement-based, both for the overall sending domain and individual accounts. Low engagement will lead to emails ending up in the spam folder, so non-engaged subscribers should be rotated out quickly.
2022-03-15 - Email Geeks
Final thoughts on deliverability
Navigating Google's dynamic email algorithms requires a proactive and engagement-focused approach for B2C senders. While dedicated IPs can offer control, they are not a substitute for strong sending practices and consistent positive engagement. Your domain's reputation, built on how recipients interact with your emails, is paramount.
Ultimately, success in email deliverability, especially with major providers like Google, hinges on being a welcome sender. This means prioritizing list quality over quantity, sending valuable content, and promptly responding to feedback (like unsubscribe requests or spam complaints). By focusing on these fundamentals, you can build a robust sender reputation that withstands algorithm updates and ensures your messages reach the inbox.
