Summary
When Senderscore indicates high email volumes despite no corresponding activity, it strongly suggests a security compromise, back-end error or misconfiguration. The causes range from compromised systems and accounts used for spam, botnet activity, and spoofed email addresses to unpatched software, soft bounces inflating volume, and misconfigured email relays. Experts and documentation agree on the need for immediate investigation, security audits, and remediation to protect sender reputation and ensure deliverability.
Key findings
- Compromised Accounts & Systems: Hacked accounts, compromised servers, and unauthorized access to email platforms are common causes.
- Botnet Activity & Malware: Compromised machines within your network may be part of a botnet, sending spam without your knowledge. Regularly scan for malware.
- Soft Bounces & Retries: Aggressive retry policies after soft bounces may inflate volume metrics reported by Senderscore.
- Spoofing: Malicious actors might be spoofing your email address to send unauthorized emails.
- Open Relays & Misconfigurations: Insecure email relay servers with open relaying enabled can be exploited. Check for misconfigurations.
- Vulnerable Software: Outdated or unpatched software exposes systems to exploits.
- Back-end Reporting Errors: ESPs might have back-end calculation errors that inflate reported email volume.
Key considerations
- Immediate Investigation: Quickly identify the source of the unexpected email volume and secure any compromised accounts or systems.
- Account Security & Access Control: Reset passwords, enforce multi-factor authentication, and revoke unnecessary API keys.
- Security Audits & Vulnerability Scans: Perform thorough security audits and vulnerability scans to identify and patch any weaknesses.
- Network Monitoring & Malware Scans: Monitor network traffic for unusual patterns and scan all systems for malware infections.
- Email Authentication (SPF, DKIM, DMARC): Ensure SPF, DKIM, and DMARC are properly configured to prevent spoofing and domain abuse.
- Review Sending Practices & Quotas: Ensure sending practices align with industry best practices and monitor/adjust sending limits and quotas.
- Blocklist Monitoring & Remediation: Check if your IP or domain is on any blocklists and take steps to request delisting if necessary.
- ESP Communication & Reporting Verification: Work with your ESP to investigate the issue, verify reporting, and review their security measures.
- Pause Sending: Temporarily pause email sending to avoid further reputation damage until the issue is resolved.
What email marketers say
9 marketer opinions
Senderscore reporting high email volumes despite no corresponding activity often indicates a security compromise. Potential causes range from hacked accounts and malware infections to misconfigured email settings or soft bounces inflating volume metrics. Immediate investigation and security measures are essential to prevent further damage to sender reputation and deliverability.
Key opinions
- Compromised Accounts: Hacked accounts or unauthorized access to email marketing platforms can lead to spam being sent from your IP.
- Malware Infections: Infected computers on your network can be used as part of a botnet to send spam.
- Soft Bounces & Retries: Aggressive retry policies after soft bounces can inflate Senderscore volume metrics.
- Spoofed Email Addresses: Someone might be spoofing your email address, sending emails that appear to come from you.
- Unpatched Vulnerabilities: Unpatched software and server vulnerabilities could be exploited to send spam through your systems.
- Blocklist Inclusion: Spam activity, regardless of origin, could cause your IP to be blocklisted, impacting Senderscore.
Key considerations
- Immediate Investigation: Quickly identify the source of the unusual email volume and secure any potentially compromised accounts.
- Password Resets: Force password resets for all users and enable two-factor authentication to improve account security.
- Security Audits: Conduct thorough security audits of your systems and network to identify vulnerabilities and malware.
- Email Authentication: Ensure SPF, DKIM, and DMARC records are properly configured to prevent email spoofing.
- Review Access Logs: Check user permissions and access logs for suspicious activity.
- Contact ESP: Contact your email service provider for assistance in identifying and resolving the issue.
- Pause Sending: Temporarily pause all email sending to prevent further damage to your IP reputation.
- Monitor Blocklists: Check if your IP address is on any public blocklists and take steps to get delisted.
- Update Software: Keep all software and systems up to date with the latest security patches.
Marketer view
Email marketer from Quora answers that if your system is sending out emails that you can't account for, there's a chance someone has gained unauthorized access to your email marketing platform. Immediately change your passwords, review user activity, and contact support.
28 Aug 2021 - Quora
Marketer view
Email marketer from Reddit's r/emailmarketing forum responds that it could be due to a compromised email account or someone spoofing your email address. The suggestion is to check SPF, DKIM, and DMARC records to ensure they are properly configured and to monitor account activity for any unusual logins or sending patterns.
17 Feb 2025 - Reddit
What the experts say
4 expert opinions
When Senderscore reports unusually high email volumes, a primary concern is a security breach. Experts suggest potential compromises such as leaked credentials, hacked systems relaying spam, or backend calculation errors by the ESP. Immediate actions involve securing accounts, auditing systems, and verifying email authentication protocols.
Key opinions
- Compromised Systems: Hackers might be using your server to relay spam without your knowledge, leading to unexpected volume.
- Account Breaches: Leaked credentials or compromised accounts are being used to send unauthorized emails.
- Backend Errors: The ESP's volume calculations might be inaccurate, leading to inflated Senderscore reports.
- DMARC Limitations: DMARC is not tied to IP and will not prevent all unauthorized sending.
Key considerations
- Security Audits: Run thorough security audits and patch any vulnerabilities immediately.
- Account Security: Review and strengthen account security practices, including enabling two-factor authentication.
- Access Control: Lock down access, revoke API keys, and shut off access for all users until the issue is resolved.
- Email Authentication: Ensure email authentication (SPF, DKIM, DMARC) is properly configured to prevent spoofing.
- Log Analysis: Examine email logs to identify the source of the unexpected traffic.
- ESP Communication: Work with your ESP to verify reporting and investigate potential causes.
Expert view
Expert from Email Geeks suggests that if both Senderscore and the ESP show the spike, and it’s no one at your organization sending it, then treat it as an account breach, lock down access hard, revoke API keys, and shut off access for all users. Also, look at the logs.
9 Dec 2022 - Email Geeks
Expert view
Expert from Word to the Wise, Laura Atkins, explains that if you're seeing unexpected email volume, it's crucial to review your account security practices, especially if you're using an ESP or shared IP space. She recommends enabling two-factor authentication, closely monitoring user access, and ensuring your email authentication (SPF, DKIM, DMARC) is properly configured to prevent spoofing.
6 Dec 2024 - Word to the Wise
What the documentation says
6 technical articles
Unexpectedly high email volumes reported by Senderscore often indicate compromised accounts, servers, or botnet activity. Documentation emphasizes the need for thorough security investigations, securing email relays, monitoring spam rates, and adhering to email sending best practices to prevent reputational damage and maintain deliverability.
Key findings
- Compromised Accounts/Servers: Sudden spikes in outbound email can be traced to compromised accounts or servers used for unauthorized sending.
- Botnet Activity: Compromised machines on your network may be part of a botnet, sending spam without your knowledge.
- Open Relays: Insecure email relay servers with open relaying enabled can be abused to send spam from your IP.
- Spam Rate Impact: High spam rates negatively impact your sender reputation and deliverability.
- Quota Exceeded: A compromised account may be exceeding sending limits, indicating unauthorized activity.
Key considerations
- Account Investigation: Investigate user accounts for suspicious activity.
- Secure Email Relays: Secure your email relay server and disable open relaying.
- Monitor Spam Rates: Monitor spam rates and sender reputation.
- Review Sending Limits: Review sending limits and quotas in your email service.
- Analyze Logs: Analyze email logs to identify the source of unexpected traffic.
- Scan for Malware: Scan your network for malware and botnet activity.
- Adhere to Guidelines: Ensure sending practices align with email provider guidelines (e.g., Google Postmaster Tools).
Technical article
Documentation from RFC-Editor suggests the importance of securing your email relay server, and ensuring open relaying is disabled. Open relays can be abused to send spam from your IP address, severely damaging your sender reputation.
4 Jan 2025 - RFC-Editor
Technical article
Documentation from Google Postmaster Tools explains that sudden spikes in reported spam rates can negatively impact your sender reputation and lead to deliverability issues. Monitor your spam rates and ensure your sending practices align with Google's guidelines.
24 Jul 2021 - Google
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