Several factors can trigger spam folder placement:

1. Authentication Issues:

• Check SPF, DKIM, and DMARC setup

• Verify proper domain alignment

• Monitor authentication pass rates

2. List Quality Factors:

• High bounce rates

• Poor engagement metrics

• Spam trap hits

• Complaint rates

3. Sending Patterns:

• Sudden volume changes

• Inconsistent sending patterns

• Poor IP/domain reputation

• Historical sending behavior

4. Resolution Steps:

• Review authentication settings

• Clean your mailing lists

• Monitor engagement metrics

• Implement sunset policies

• Follow sender best practices

• Consider IP/domain warm-up

• Monitor spam complaint rates

For specific spam folder issues, review your Health Score and analytics for detailed insights into potential causes.