// how to fix

How to fix email problems

Your test or scan found a problem? Find the matching guide below: what it means, why it matters, and how to fix it step by step.

DNS 33 DMARC 28 SPF 28 DKIM 26 Reputation 24 Bounce 16 Security 16 Blacklist 13 Gmail 13 Content 12 Mailing list 11 Spam score 10 Headers 9 Reverse DNS 7 Mail server 4 Microsoft 365 4 MX 4 Outlook 4 TLS 2 Apple 1 BIMI 1 E-commerce 1 Google Workspace 1 WordPress 1 Yahoo 1 Zoho 1

10 guides · tag Spam score

Problem	In short	Tags
High SpamAssassin spam score	SpamAssassin scores the content of your email. Above 5, it is treated as spam. Learn what raises the score and how to bring it down.	Spam score	Fix it
Gmail and Yahoo bulk sender requirements	Since 2024, Gmail and Yahoo require large senders to authenticate their emails, offer one-click unsubscribe and keep spam complaints very low. Here is the checklist.	Gmail DMARC Spam score	Fix it
Your emails land in Gmail's spam folder	When Gmail sends your emails to spam, the cause is almost always authentication, reputation or content. Here is how to find which one and fix it.	Gmail Reputation Spam score	Fix it
Add a List-Unsubscribe header (one-click unsubscribe)	The List-Unsubscribe header lets Gmail, Yahoo and Outlook show an Unsubscribe button next to your sender name. Bulk senders must offer it in one click.	Headers Gmail Spam score	Fix it
Invalid HELO/EHLO hostname	Your server introduces itself with a name that is not valid, such as localhost or a bare IP. Spam filters distrust this. Give it a real name that matches reverse DNS.	Reverse DNS DNS Spam score	Fix it
Links that hurt deliverability	URL shorteners, link text that shows one address but points to another, and links to blacklisted domains are classic spam signs. Use plain links to your own domain.	Content Blacklist Spam score	Fix it
Image-only emails and missing plain-text version	An email that is one big image, or that has no plain-text version, looks like spam to filters. Use real text, a few images, and send both HTML and plain text.	Content Spam score	Fix it
Cold emailing without landing in spam	Prospecting emails are judged harshly by Gmail and Outlook. Protect your main domain, send slowly, write like a person and make opting out easy.	Reputation Content Spam score	Fix it
Missing or wrong Date and Message-ID headers	Every email should carry a correct Date and a unique Message-ID. Without them, spam filters add points and Gmail can refuse the email.	Headers Spam score Gmail	Fix it
Spammy subject lines and words that trigger filters	Shouting subjects, fake urgency and pushy money words make filters and readers suspicious. Write calm, honest subjects that match the content.	Content Spam score	Fix it

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