{
  "id": "communication/smtp-554-transaction-failed-spam",
  "signature": "SMTP 554 5.7.1 Transaction failed: message content rejected as spam",
  "signature_zh": "SMTP 554 5.7.1 事务失败：邮件内容被拒绝为垃圾邮件",
  "regex": "554\\s+5\\.7\\.1\\s+Transaction\\s+failed.*spam",
  "domain": "communication",
  "category": "auth_error",
  "subcategory": null,
  "root_cause": "Receiving mail server rejects the message because its content or headers trigger spam filters, often due to high link-to-text ratio, suspicious keywords, or missing DMARC policy alignment.",
  "root_cause_type": "generic",
  "root_cause_zh": "接收邮件服务器拒绝邮件，因为其内容或标头触发垃圾邮件过滤器，通常是由于链接与文本比例过高、可疑关键词或缺少 DMARC 策略对齐。",
  "versions": [
    {
      "version": "Postfix 3.7.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Exim 4.96",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "Microsoft Exchange Online",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    },
    {
      "version": "SpamAssassin 4.0.0",
      "introduced": null,
      "deprecated": null,
      "removed": null,
      "behavior_change": null,
      "status": "active"
    }
  ],
  "os_specific": {},
  "dead_ends": [
    {
      "action": "",
      "why_fails": "Whitelisting the sending IP in the receiving server may bypass spam filters temporarily, but the message content itself remains flagged, leading to eventual rejection or quarantine.",
      "fail_rate": 0.6,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Adding more DKIM signatures (e.g., multiple selectors) doesn't address content-based filtering and may confuse the receiving server's authentication chain.",
      "fail_rate": 0.8,
      "condition": "",
      "sources": []
    },
    {
      "action": "",
      "why_fails": "Reducing the sending rate (e.g., 1 email per minute) doesn't change the message content; spam filters still evaluate each message independently.",
      "fail_rate": 0.7,
      "condition": "",
      "sources": []
    }
  ],
  "workarounds": [
    {
      "action": "Review and sanitize email content: remove excessive links, avoid spammy keywords (e.g., 'free', 'click here', 'urgent'), and ensure a balanced text-to-image ratio. Use a spam testing tool like Mail-Tester to pre-check.",
      "success_rate": 0.85,
      "how": "Review and sanitize email content: remove excessive links, avoid spammy keywords (e.g., 'free', 'click here', 'urgent'), and ensure a balanced text-to-image ratio. Use a spam testing tool like Mail-Tester to pre-check.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Configure DMARC policy to 'p=reject' or 'p=quarantine' and ensure SPF/DKIM alignment passes: verify the 'From' domain matches the DKIM signing domain and SPF envelope sender domain.",
      "success_rate": 0.8,
      "how": "Configure DMARC policy to 'p=reject' or 'p=quarantine' and ensure SPF/DKIM alignment passes: verify the 'From' domain matches the DKIM signing domain and SPF envelope sender domain.",
      "condition": "",
      "sources": []
    },
    {
      "action": "Use a dedicated email sending service (e.g., SendGrid, AWS SES) with pre-warmed IPs and built-in spam compliance to handle content delivery, bypassing direct SMTP.",
      "success_rate": 0.9,
      "how": "Use a dedicated email sending service (e.g., SendGrid, AWS SES) with pre-warmed IPs and built-in spam compliance to handle content delivery, bypassing direct SMTP.",
      "condition": "",
      "sources": []
    }
  ],
  "workarounds_zh": [
    "Review and sanitize email content: remove excessive links, avoid spammy keywords (e.g., 'free', 'click here', 'urgent'), and ensure a balanced text-to-image ratio. Use a spam testing tool like Mail-Tester to pre-check.",
    "Configure DMARC policy to 'p=reject' or 'p=quarantine' and ensure SPF/DKIM alignment passes: verify the 'From' domain matches the DKIM signing domain and SPF envelope sender domain.",
    "Use a dedicated email sending service (e.g., SendGrid, AWS SES) with pre-warmed IPs and built-in spam compliance to handle content delivery, bypassing direct SMTP."
  ],
  "transition_graph": {
    "leads_to": [],
    "preceded_by": [],
    "frequently_confused_with": []
  },
  "official_doc_url": "https://www.rfc-editor.org/rfc/rfc5321#section-4.2.5",
  "official_doc_section": null,
  "error_code": "554 5.7.1",
  "verification_tier": "ai_generated",
  "confidence": 0.86,
  "fix_success_rate": 0.83,
  "resolvable": "true",
  "first_seen": "2024-03-05",
  "last_confirmed": "2024-06-01",
  "last_updated": "2024-06-01",
  "evidence_count": 1,
  "tags": [],
  "locale": "en",
  "aliases": []
}