title: Mail Protocols (T1071.003)
id: df00tech-t1071-003
status: experimental
description: "Adversaries may communicate using application layer protocols associated with electronic mail delivery to avoid detection/network filtering by blending in with existing traffic. Commands to the remote system, and often the results of those commands, will be embedded within the protocol traffic between the client and server. Protocols such as SMTP/S, POP3/S, and IMAP that carry electronic mail may be very common in environments. Packets produced from these protocols may have many fields and headers in which data can be concealed. Data could also be concealed within the email messages themselves. An adversary may abuse these protocols to communicate with systems under their control within a victim network while also mimicking normal, expected traffic."
references:
  - https://attack.mitre.org/techniques/T1071/003/
  - https://df00tech.com/detections/T1071.003
author: df00tech
date: 2026/04/13
tags:
  - attack.t1071.003
# NOTE: logsource is auto-derived and may need adjustment for your environment
logsource:
  category: network_connection
  product: windows
detection:
  # This detection logic could not be auto-translated; see the KQL/SPL query on df00tech.
  selection:
    EventID: '*'
  condition: selection
falsepositives:
  - "Scripted email sending tools used by IT for automated notifications (e.g., Python scripts using smtplib, PowerShell Send-MailMessage)"
  - "Application servers with built-in email notification capabilities (monitoring alerts, report delivery)"
  - Email security gateways and spam filters that relay mail through non-standard processes
  - Backup software that sends completion notifications via SMTP
level: high