What does “message rejected due to spam content” mean?

"Message rejected due to spam content" indicates content filtering rejection:

What triggered it:

Text patterns: Spam trigger words or phrases. Formatting: Excessive caps, punctuation, or colors. URLs: Links to suspicious domains. Structure: Image-heavy with little text. Signatures: Known spam patterns matched.

Content elements to review:

Subject line for trigger words. Body text for spam phrases. All URLs for blocklist status. Attachment types and names. HTML code for hidden content.

Resolution steps:

Review and clean content. Remove or replace suspicious URLs. Improve text-to-image ratio. Test with spam checkers before sending. Consider warming the content gradually.

Content rejection means your message looks like spam. Clean it up to pass the smell test.