MailEnum — IMAPS / POP3S Enumeration Toolkit

A Python-based mail service enumeration tool designed for authorized penetration testing, CTFs, and security labs. MailEnum connects to IMAPS/POP3S services, performs automatic enumeration, exposes available mailboxes/messages, and provides OpenSSL-based TLS inspection.

⚠️ Disclaimer: Use this tool only against systems you own or have explicit permission to test. Do not use it to access or modify unauthorized mailboxes.

Features 🔐 IMAPS

MailEnum supports:

IMAPS connection over TLS Username/password authentication IMAP CAPABILITY enumeration IMAP ID enumeration Automatic mailbox discovery Mailbox status enumeration Mailbox selection Message enumeration Message header retrieval Complete message retrieval Message searching Message deletion Mailbox creation Mailbox deletion Mailbox renaming Re-enumeration of mailboxes 📬 POP3S

Supports:

POP3S connection over TLS Authentication CAPA enumeration Maildrop STAT Message LIST Message header retrieval using TOP Complete message retrieval using RETR Message deletion using DELE 🔎 TLS / OpenSSL

MailEnum also integrates OpenSSL functionality:

TLS connection testing TLS protocol detection Cipher enumeration Server certificate inspection Certificate subject Certificate issuer Certificate validity dates Subject Alternative Names SHA-256 certificate fingerprint openssl s_client integration Workflow

The tool follows an enumeration-first workflow.

                ┌───────────────┐
                │ Start MailEnum │
                └───────┬───────┘
                        │
                        ▼
              ┌───────────────────┐
              │ Enter Target Host │
              └─────────┬─────────┘
                        │
                        ▼
             ┌────────────────────┐
             │ Select IMAPS/POP3S │
             └──────────┬─────────┘
                        │
                        ▼
             ┌────────────────────┐
             │ Username / Password│
             └──────────┬─────────┘
                        │
                        ▼
              ┌──────────────────┐
              │ TLS Enumeration  │
              └────────┬─────────┘
                       │
                       ▼
             ┌────────────────────┐
             │ Automatic Service  │
             │    Enumeration     │
             └──────────┬─────────┘
                        │
             ┌──────────┴──────────┐
             │                     │
             ▼                     ▼
          IMAPS                  POP3S
             │                     │
             ▼                     ▼
       List Mailboxes         List Messages
             │                     │
             ▼                     ▼
      Select Mailbox         Select Message
             │                     │
             ▼                     ▼
   Message Operations       Message Operations

Requirements Operating System

Linux is recommended.

Tested primarily in security-lab environments such as:

Ubuntu Kali Linux Debian-based distributions Python

Python 3.8+ is recommended.

No third-party Python packages are required if the tool uses the standard-library implementation.