Why are my email newsletters going to the spam folder in Gmail?
Matthew Whittaker
Co-founder & CTO, Suped
Published 4 Jun 2025
Updated 16 Aug 2025
7 min read
It can be incredibly frustrating to discover your email newsletters are consistently landing in the spam folder, especially when you've put effort into crafting valuable content. Many senders experience this challenge with Gmail, a provider known for its sophisticated spam filtering algorithms that prioritize user experience.
The problem often isn't a single issue but a combination of factors, ranging from technical misconfigurations to content quality and subscriber engagement. Understanding these elements is key to improving your newsletter's inbox placement.
Authentication and sender reputation
Email authentication protocols like SPF, DKIM, and DMARC are fundamental to proving your legitimacy as a sender. Gmail heavily relies on these to verify that emails are indeed coming from the domain they claim to be from, preventing spoofing and phishing. If these records are missing or incorrectly configured, your newsletters are very likely to be flagged as suspicious and sent directly to spam (or junk) folders.
Sender reputation, which is built over time, also plays a crucial role. This reputation is influenced by various metrics, including your spam complaint rate, bounce rate, and user engagement. A poor reputation tells Gmail that your emails are unwanted or potentially malicious, leading to increased spam filtering. It's a cumulative score, so consistent good sending practices are essential.
It's not uncommon for legitimate senders to suddenly see their emails going to spam in Gmail. Often, this is due to recent shifts in authentication requirements or a decline in sender reputation stemming from subtle issues over time. Regularly monitoring your authentication status and sender scores can help you catch problems before they significantly impact deliverability.
Common authentication issues
Missing SPF record: No authorized sender policy framework (SPF) record published for your domain.
Incorrect DKIM setup: Your domain keys identified mail (DKIM) signature is invalid or not aligning.
Gmail's spam filters are incredibly sophisticated and pay close attention to the content of your newsletters. They're designed to identify characteristics commonly associated with unwanted emails, such as excessive use of all caps, too many exclamation marks, generic subject lines, or a disproportionate ratio of images to text. While there isn't a definitive list of 'spam trigger words,' certain phrases can contribute to a higher spam score, especially when combined with other red flags.
Beyond the technical aspects, user engagement is a powerful signal for Gmail. If subscribers consistently open, click, reply, or move your newsletters from their spam folder to their inbox, Gmail learns that your content is valued. Conversely, if your emails are frequently deleted without being opened, marked as spam, or simply ignored, this negatively impacts your sender reputation and can lead to future emails being sent to the spam folder. Gmail's filtering is highly individualized, meaning a newsletter might land in one user's inbox but another's spam folder based on their personal engagement history. This is true for transactional emails too, which can suddenly go to spam.
Moreover, if your emails consistently go to the Promotions tab in Gmail, it suggests that Gmail recognizes them as marketing content rather than primary correspondence. While not the spam folder, it indicates your content type, and sustained low engagement within that tab can also lead to spam placement. This is why it's vital to create content that genuinely resonates with your audience and encourages interaction.
High engagement
Personalized content: Tailoring newsletters to individual subscriber interests and behaviors.
Clear call-to-action: Encouraging clicks, replies, and forwards through compelling messaging.
Interactive elements: Including quizzes, polls, or dynamic content to boost interaction.
Low engagement & spam signals
Generic subject lines: Failing to entice opens with vague or uninteresting titles.
Image-heavy emails: Too many images or large image files can trigger filters.
Lack of plain text alternative: Absence of a plain text version for HTML emails.
List hygiene and engagement
Sending newsletters to an unengaged or outdated list is a surefire way to damage your sender reputation and increase your chances of landing in the spam folder. Gmail's algorithms closely monitor how recipients interact with your emails. If a significant portion of your list isn't opening, clicking, or is marking your emails as spam, it signals to Gmail that your messages are not desired, leading to more aggressive filtering.
Hard bounces, which occur when emails are sent to invalid or non-existent addresses, are particularly damaging. These indicate poor list hygiene and can severely impact your sender score. Similarly, hitting spam traps (also known as honeypots) created by mailbox providers to catch senders with bad practices, will instantly tank your reputation and likely get your IP address or domain blacklisted (or blocklisted).
Implementing a double opt-in process for new subscribers is crucial. This ensures that only genuinely interested individuals are added to your list, significantly reducing the likelihood of spam complaints and improving overall engagement. Regularly cleaning your email list to remove inactive subscribers and invalid addresses is also a key best practice for maintaining a healthy sender reputation.
Issue
Impact on deliverability
Solution
High bounce rates
Signals a poor quality list, leading to reduced sender reputation.
Regularly remove hard bounces and monitor soft bounces for persistent issues.
Low engagement
Gmail filters based on individual user behavior, pushing unengaged newsletters to spam.
Directly signals to Gmail that recipients don't want your emails, leading to blocklisting (or blacklisting).
Ensure clear opt-in and easy unsubscribe links. Monitor complaint rates in Google Postmaster Tools.
Technical and compliance issues
Even with perfect authentication and a healthy list, technical issues can derail your newsletter deliverability. For instance, sending emails from a shared IP address that has a poor reputation due to other senders' bad practices can inadvertently affect your own emails. While dedicated IPs offer more control, they also require careful management of your own sending volume and reputation.
Compliance with email marketing regulations, such as the CAN-SPAM Act, is also critical. Failing to include a clear unsubscribe link, a physical address, or misrepresenting your sender information can lead to your newsletters being marked as spam and even legal repercussions. These aren't just legal requirements, but also best practices that build trust with your subscribers and mailbox providers.
Your email service provider (ESP) or SMTP server's reputation also plays a role. If your provider has a history of allowing spammy behavior, their shared IP addresses might be on blocklists, impacting your deliverability. Always choose a reputable provider with a strong focus on deliverability and compliance. Sometimes, using Gmail's SMTP for bulk sends can also lead to issues due to their stricter policies for mass email.
Finally, ensure your email's HTML and coding are clean and well-structured. Poorly coded emails, broken links, or excessive attachments can raise red flags for spam filters. A simple, mobile-responsive design that loads quickly and displays correctly across different email clients is always the safest bet.
Views from the trenches
Best practices
Actively manage your email list by regularly removing inactive subscribers to boost engagement rates and sender reputation.
Always use a double opt-in process for new subscribers to ensure high-quality, engaged leads.
Consistently monitor your authentication records (SPF, DKIM, DMARC) for proper configuration and alignment.
Craft engaging and relevant content that encourages opens, clicks, and replies to signal value to mailbox providers.
Ensure your email templates are clean, responsive, and avoid excessive images or 'spammy' keywords.
Common pitfalls
Sending to purchased or old lists, which can contain spam traps and significantly damage your domain's reputation.
Ignoring low open rates and high bounce rates, as these metrics directly influence spam folder placement.
Failing to set up or incorrectly configuring email authentication protocols, leading to messages being flagged as spoofed.
Using generic subject lines or overly promotional language that triggers spam filters.
Not providing a clear and easy-to-find unsubscribe option, which can lead to high spam complaint rates.
Expert tips
Segmenting your audience and tailoring content to specific interests can dramatically improve engagement and deliverability.
Leverage Google Postmaster Tools to gain insights into your sender reputation, spam rates, and authentication errors.
Periodically send re-engagement campaigns to inactive subscribers before removing them to attempt to rekindle interest.
Consider warming up new IP addresses or domains gradually to build a positive sending history.
Regularly test your email deliverability to various mailbox providers to identify potential issues before they become widespread problems.
Marketer view
Marketer from Email Geeks says they started seeing a lot of mail from senders they've received for a long time going to spam in their Workspace account.
2022-09-13 - Email Geeks
Marketer view
Marketer from Email Geeks says they strongly suspect the lack of engagement is the reason, as it affects all kinds of automated emails, not just marketing ones.
2022-09-13 - Email Geeks
Improving newsletter inbox placement
The deliverability of your email newsletters to Gmail inboxes is a multifaceted challenge that requires a holistic approach. It's not just about avoiding 'spammy' content or having perfect technical setup, but also about building and maintaining a strong sender reputation through consistent positive engagement.
By prioritizing robust authentication, delivering valuable and engaging content, maintaining excellent list hygiene, and addressing any underlying technical issues, you can significantly improve your newsletter's chances of reaching the primary inbox. Continuously monitor your performance and adapt your strategies to Gmail's evolving filtering mechanisms.
