March 12th, 2026
A local business organization contacted Dextect after noticing suspicious email activity in one of their Microsoft 365 accounts. The account had begun generating large numbers of “undeliverable” messages, a common indicator that a mailbox may have been involved in a spam or spoofing incident.
A local business organization contacted Dextect after noticing suspicious email activity in one of their Microsoft 365 accounts. The account had begun generating large numbers of “undeliverable” messages, a common indicator that a mailbox may have been involved in a spam or spoofing incident.
The concern was twofold:
• Protect the organization’s reputation and email deliverability
• Ensure their email system was secured to prevent future misuse
After reviewing the account and domain configuration, we identified several issues that made the system vulnerable to spoofing and misuse:
• Insufficient email authentication protections
• Inbox clutter caused by automated bounce messages
• Lack of centralized monitoring for suspicious activity
While the account itself had not been fully compromised, the configuration left the organization exposed to potential spoofing attempts.
Dextect quickly implemented several corrective measures:
Email Security Hardening
We configured proper email authentication protections including:
• SPF
• DKIM
• DMARC enforcement
These protocols help prevent bad actors from impersonating the organization’s email domain.
Inbox Cleanup
We implemented automated inbox rules to remove thousands of undeliverable bounce messages and restore the inbox to normal operation.
Security Review
We reviewed account security settings and provided recommendations to strengthen:
• password practices
• multi-factor authentication
• internal security awareness
Within the same evening:
• Email deliverability was restored
• Spoofing protections were fully configured
• The mailbox was cleaned and stabilized
• The organization gained stronger domain security
Most importantly, the organization now has safeguards in place to help prevent similar issues in the future.
Email is the backbone of communication for most organizations, but many small teams don’t realize their domain may not be fully protected.
Without proper protections like SPF, DKIM, and DMARC, attackers can attempt to impersonate your domain to send fraudulent emails.
Dextect helps small businesses prevent these risks through proactive monitoring, security configuration, and ongoing support.
Dextect provides ongoing security monitoring and IT support for small businesses.
Book a consultation to review your email security and IT setup.