Why are my emails landing in spam even though they pass SPF, DKIM, and DMARC?
Summary
What email marketers say10Marketer opinions
Email marketer from GlockApps shares that using a deliverability testing tool can identify specific issues causing spam placement, such as content issues or problems with specific mailbox providers, despite passing authentication.
Email marketer from Reddit explains that low engagement rates (opens, clicks) signal to mailbox providers that your emails are unwanted, leading to spam placement despite proper authentication. They suggest focusing on list hygiene and relevant content.
Email marketer from Litmus explains that poorly designed emails, with broken HTML, missing alt text, or excessive use of images, can trigger spam filters even if authentication is properly configured.
Email marketer from Lemlist recommends personalizing emails to increase engagement and avoid spam filters. Generic, mass-sent emails are more likely to be flagged as spam, even with proper authentication.
Email marketer from SendPulse shares that spam filters analyze email content for suspicious keywords, excessive links, and poor formatting. Even authenticated emails can be flagged if the content resembles spam.
Email marketer from Woodpecker shares that a new IP address needs to be 'warmed up' gradually by sending small volumes of emails initially to build a positive sender reputation. Sending large volumes immediately from a new IP will likely result in spam placement.
Email marketer from Email Deliverability Forum responds that your sending IP or domain may be listed on a blocklist despite not showing up on major blacklist checks. Smaller, industry-specific blocklists can still affect deliverability.
Email marketer from Autopilot shares that sending too many emails too frequently can lead to users marking your emails as spam. Sending emails too infrequently causes users to forget who you are so engagement is negatively impacted.
Email marketer from Mailjet explains that inbox placement depends on sender reputation, engagement, and content quality, in addition to authentication. Even with proper SPF, DKIM, and DMARC, poor sender reputation or low engagement can lead to spam classification.
Email marketer from EmailToolTester explains that using a shared IP address, especially a 'dirty' one, can negatively impact deliverability even with SPF, DKIM, and DMARC in place. A dedicated IP is recommended for larger senders.
What the experts say6Expert opinions
Expert from Email Geeks explains it is much harder than B2C where you have (in theory) higher volumes and more touch points with which to adjust the rudder to steer your reputation.
Expert from Spamresource shares that even with perfect technical setup (SPF, DKIM, DMARC), poor sender reputation can override authentication and cause emails to land in spam. Reputation is built over time based on user engagement and sending practices.
Expert from Word to the Wise explains that high complaint rates (users marking emails as spam) are a major factor in spam filtering. Even with proper authentication, a high complaint rate will negatively impact deliverability.
Expert from Email Geeks responds that it could just be low domain reputation, which is hard to fix with low send volume.
Expert from Word to the Wise shares that sending to old or unengaged email addresses can significantly impact deliverability. Maintaining a clean and engaged email list is crucial for avoiding spam filters, even with proper authentication.
Expert from Spamresource explains that content filters analyze email content for spam-like characteristics. Even with authentication, using certain keywords, phrases, or excessive HTML can trigger spam filters.
What the documentation says4Technical articles
Documentation from RFC explains that DMARC policy settings (p=quarantine or p=reject) impacts what happens to messages failing authentication. The DMARC policy needs to be set to gradually increase to ensure all legitimate emails are authenticating correctly.
Documentation from SparkPost shares that high bounce rates can negatively impact a sender’s reputation, leading to increased spam filtering. It’s important to regularly clean email lists and remove invalid addresses.
Documentation from Microsoft SNDS (Smart Network Data Services) shares that negative feedback from users (e.g., marking emails as spam) significantly impacts your sender reputation and deliverability to Outlook.com and Hotmail users, even with proper authentication.
Documentation from Google Postmaster Tools explains that a sender's IP and domain reputation significantly impacts deliverability to Gmail users. Even with authentication, a poor reputation due to past sending practices can lead to spam filtering.