Unattended Emails: A Cyber Risk Organizations Should Not Overlook After the Holidays

The period following long holidays—such as New Year or major festivals—is often seen as a “return to normal operations.”
However, from a cyber attacker’s perspective, this is a high-risk window, particularly for email phishing campaigns that remain in employees’ inboxes.

Many malicious emails are sent during the holiday period but are not opened immediately.
They are instead opened after the holidays, when employees rush to clear large volumes of emails in a short time.

Why Old Emails Become High-Risk

Analysis of multiple cybersecurity incidents reveals a recurring pattern:

• IT and SOC teams operate with reduced capacity during holidays
• Some alerts or warnings are delayed or postponed
• Employees open large volumes of emails under time pressure
• Verification of sender, domain, and links is often overlooked

As a result, phishing emails that bypassed detection during holidays can become the starting point for serious incidents, including:

• Credential compromise
• Malware infection
• Ransomware attacks

Phishing Does Not End With the Holidays

Many organizations assume:

“If we get through the holiday period, we are safe.”

In reality, email phishing often works as a time-delayed attack:

• Emails are sent when monitoring systems are less active
• They wait to be opened when users return and rush through their inbox
• Urgent-sounding content such as invoices, account updates, or HR notifications is used to prompt quick action

An “unattended” email is therefore not just old mail, but an unmanaged risk.

Immediate Measures Organizations Should Take

1. Establish a “Post-Holiday Email Awareness” Policy

• Communicate to employees to remain cautious with emails sent before the holiday
• Emphasize that old emails ≠ safe emails
  
  

2. Systematically Verify Sender and Domain

• Check sender names, domain authenticity, and content consistency
• Be cautious of lookalike domains
  
  

3. Avoid Clicking Links or Opening Attachments Without Verification

• Especially invoices, ZIP files, HTML attachments, or links requiring login
  
  

4. Strengthen Systemic Measures

• Email Security Gateways
• DMARC / SPF / DKIM
• Phishing simulations & Security Awareness Training

Conclusion for IT and Security Leaders

The post-holiday period is not a time to relax on cybersecurity.
It is a time to increase vigilance, because for attackers:

“Unattended emails” are still open vulnerabilities.

Building a culture of awareness alongside appropriate security controls is key to mitigating risks that can start with just a single email.

#bigfishtechnology #bigfishtec #Cybersecurity #EmailSecurity #PhishingAwareness #DigitalRisk #EnterpriseSecurity