Emails may go to the spam folder for several reasons, primarily due to filters designed to protect users from unwanted or malicious messages. Here are common causes and examples:
Sender Reputation: If the sender's IP or domain has a history of sending spam, emails are likely flagged. For example, a new domain with no prior email history may trigger spam filters.
Example: A startup using a newly registered domain sends bulk emails without proper authentication (like SPF/DKIM), causing emails to land in spam.
Content Triggers: Emails containing spam-like keywords (e.g., "free," "win," "urgent") or excessive links/images may be flagged.
Example: An email with the subject line "Congratulations! You’ve Won a Prize!" is often marked as spam.
User Behavior: If recipients frequently mark emails from a sender as spam, future messages are automatically filtered.
Example: A newsletter sender ignores unsubscribe requests, leading users to report spam, which trains filters against the sender.
Lack of Authentication: Missing SPF, DKIM, or DMARC records makes emails appear suspicious.
Example: An email without DKIM signing is more likely to be flagged as spam.
Email Service Provider Rules: Providers like Gmail or Outlook use machine learning to detect spam patterns, sometimes misclassifying legitimate emails.
Example: A promotional email from a small business may be flagged if it resembles past spam campaigns.
Recommendation: Use Tencent Cloud’s Email Delivery Service to improve deliverability. It provides SPF, DKIM, and DMARC authentication, helps monitor sender reputation, and optimizes email content to reduce spam flagging.