Why are my emails still going to spam despite good practices?
Michael Ko
Co-founder & CEO, Suped
Published 7 Jul 2025
Updated 18 Aug 2025
7 min read
It is frustrating when you feel like you have done everything right with your email setup, yet your messages still end up in the spam folder. You have opted-in subscribers, no purchased lists, a good IP score, and all your authentication records (SPF, DKIM, DMARC) are in place. You have even checked Google Postmaster Tools and everything looks fine. So, what is going on? Why are your emails still going to spam despite good practices?
The truth is, email deliverability is a complex puzzle with many pieces. While the foundational elements like authentication and list hygiene are critical, there are often deeper, less obvious factors at play that can still push your emails into the junk or blocklist (blacklist) folders. It requires a detailed investigation to pinpoint the exact cause when the obvious solutions do not work.
Mailbox providers like Gmail and Outlook (Hotmail) use sophisticated algorithms that look at hundreds of signals beyond just your basic setup. This guide will explore some of these less-talked-about reasons and provide actionable insights to help you get your emails into the inbox, not the junk folder.
Technical authentication nuances
Many senders correctly implement SPF, DKIM, and DMARC, believing this fully addresses authentication. However, simply having these records is not always enough. The alignment of your DMARC records plays a critical role, as does the consistent application of these standards across all your sending systems.
If your DMARC authentication policy is set to `p=none` for an extended period, it might not be sending a strong enough signal to mailbox providers that you are serious about preventing abuse of your domain. While `p=none` is a good starting point for monitoring, it does not instruct receiving servers to quarantine or reject unauthenticated emails. Moving to a `p=quarantine` or `p=reject` policy, even partially, can significantly boost your perceived trustworthiness.
Another subtle issue can be the use of subdomains or third-party senders. Each subdomain needs proper authentication. If you use a third-party email service provider (ESP), ensure their configuration aligns correctly with your primary domain for SPF and DKIM. Sometimes, even if you pass SPF, DKIM, and DMARC, other factors might be at play.
Common technical oversights
DNS propagation: New DNS changes for SPF, DKIM, or DMARC might take time to fully propagate. A staggered deployment or caching could lead to inconsistent results across different receiving mail servers.
SPF DNS lookups: Too many DNS lookups in your SPF record (exceeding the 10-lookup limit) can cause SPF to fail, even if the record itself appears correct. This is a common issue for businesses using multiple sending services.
DKIM key rotation: Infrequent DKIM key rotation can sometimes be seen as a security weakness by strict filters, though this is less common than other issues.
Also, consider if any temporary errors are causing issues. For example, DKIM `temperror` can be a sign of DNS resolution problems that intermittently prevent successful authentication, leading to spam placement even with a seemingly good setup.
Sender and domain reputation
While you might have a good Return Path IP score or positive signals in Google Postmaster Tools, sender reputation is multifaceted. It is not just about your IP address, but also your domain and content. Different Internet Service Providers (ISPs) and mailbox providers weigh these factors differently.
For instance, an IP with a good score might still be associated with a domain that has a poor reputation due to past sending behaviors, even if those behaviors have stopped. This can be particularly true if you have recently acquired a new domain or if a previous owner of your domain had poor sending practices. Domain age and history can influence how Google Postmaster Tools domain reputation views your domain.
Your sending volume and consistency also play a role. Sudden spikes in volume, even for legitimate marketing emails, can trigger spam filters, particularly if you are sending to a new segment of your list or to less engaged subscribers. Gradual list growth and consistent sending volumes are preferred.
Spam complaints: Even a small number of direct spam complaints from recipients can significantly damage your sender reputation, especially if concentrated at specific mailbox providers. Your email spam rate should be very low.
Unknown users/bounces: Sending to invalid or non-existent email addresses (hard bounces) inflates your bounce rate and signals poor list hygiene, which can negatively impact deliverability.
Content and recipient engagement
Even with perfect authentication and a stellar reputation, your email content itself can be a major factor in spam placement. This goes beyond obvious spammy keywords. Modern spam filters are highly sophisticated and analyze the entire email for patterns indicative of unwanted mail.
Consider your image-to-text ratio. Emails that are predominantly images with very little text can be flagged as suspicious, as spammers often use images to bypass text-based filters. Similarly, excessive use of bolding, different font sizes, or unusual character sets can raise red flags. Avoiding email spam filters often means keeping your design balanced and clean.
Recipient behavior is also paramount. If subscribers consistently ignore your emails, move them to junk, or delete them without opening, mailbox providers learn to send your messages straight to spam. Conversely, if recipients actively engage (open, click, reply, move to primary inbox), it sends strong positive signals. This is why you might see emails going to Gmail spam even with high open rates, because other engagement metrics might be lacking.
Content pitfalls
Broken links: Links that lead to non-existent pages, or suspiciously short/redirected URLs, can trigger filters.
Excessive tracking: Overly complex tracking parameters on links can sometimes appear suspicious.
Unsubscribe link: Missing or hard-to-find unsubscribe options are a major red flag for both filters and recipients.
Recipient behavior impact
Low engagement: If recipients consistently ignore or delete your emails, it indicates disinterest, signaling to filters that your emails are not valuable.
List decay: Over time, even opted-in lists can accumulate inactive addresses or spam traps. Regularly cleaning your list is crucial.
Folder placement: If users frequently move your emails from the primary inbox to other folders or the junk folder, this trains the ISP to filter your mail more aggressively.
Shared IP environments and warming
Using an email service provider (ESP) like Click Dimensions means you are likely sending from shared IP addresses. While reputable ESPs manage their IPs carefully, the actions of other senders on those shared IPs can still impact your deliverability. If another user on your shared IP sends out a spam campaign, your emails could suffer even if your own practices are good.
Furthermore, even with good initial practices, a lack of proper IP or domain warm-up can cause problems, especially when sending from new infrastructure or to new segments. Even if you have good domain reputation, a new IP needs to build its own reputation by sending low volumes initially and gradually increasing them.
It is also worth investigating if you are inadvertently hitting spam traps. These are email addresses designed to catch senders who do not practice good list hygiene. Hitting spam traps, even occasionally, can lead to your emails being directed to the spam or junk folder across various providers.
Finally, review any blocklist (blacklist) listings. While you may not be on major public blocklists, some private or internal blocklists used by specific mailbox providers could be affecting you. You can use a blocklist checker to see if your IP or domain is listed on any of the common ones.
Concluding thoughts
Successfully delivering emails requires continuous monitoring and adaptation to evolving mailbox provider rules. Even when following all known best practices, subtle issues related to authentication alignment, specific ISP reputation nuances, content structure, recipient engagement, or shared IP environments can still cause deliverability problems.
It is not a one-time setup, but an ongoing process of optimization and troubleshooting. By delving deeper into these less obvious factors, you can identify the root causes of spam placement and significantly improve your inbox deliverability rates.
Views from the trenches
Best practices
Maintain meticulous list hygiene by regularly removing inactive subscribers and hard bounces.
Segment your audience based on engagement and send more frequently to highly engaged users.
Always include a clear and easy-to-find unsubscribe link in every email.
Gradually increase your sending volume, especially when sending to new domains or IP addresses.
Monitor specific ISP feedback loops and postmaster tools for detailed insights into deliverability issues.
Common pitfalls
Assuming full authentication (SPF/DKIM/DMARC) guarantees inbox placement without considering alignment.
Ignoring subtle content issues like image-to-text ratio or excessive formatting that trigger spam filters.
Not considering the impact of shared IP reputation, particularly when using an ESP.
Sending to unengaged segments or old lists, which can increase spam complaints and low engagement signals.
Overlooking private blocklists or specific ISP filtering rules that differ from general reputation scores.
Expert tips
Use a dedicated sending IP if your volume justifies it to have more control over your reputation.
Implement BIMI to further enhance brand trust and email authentication for supported clients.
Test your emails with an email deliverability tester before sending to identify potential issues.
Engage in re-engagement campaigns for inactive subscribers or remove them from your active lists.
Analyze DMARC reports thoroughly to identify specific authentication failures or alignment issues.
Marketer view
Marketer from Email Geeks says they generally try to send the exact same content from a different fully authenticated domain. If that email hits the inbox, then there is a strong chance the domain reputation is at issue, not the content.
2019-05-01 - Email Geeks
Marketer view
Marketer from Email Geeks says to figure out which domain or domains are getting blocked and then start sending email really slowly to rebuild trust.
Gmail
and 
Outlook (Hotmail) use sophisticated algorithms that look at hundreds of signals beyond just your basic setup. This guide will explore some of these less-talked-about reasons and provide actionable insights to help you get your emails into the inbox, not the junk folder.
