From 644926a36114b7c7c129af287f379e5e875fa1aa Mon Sep 17 00:00:00 2001
From: sherlock <git@aaditagrawal.com>
Date: Mon, 24 Mar 2025 03:41:40 +0530
Subject: [PATCH] feat: add SMTP server and mail sender scripts
Implement an SMTP server using aiosmtpd and a mail sender script. The
server handles incoming messages and prints their content, while the
mail sender constructs and sends an email message. These changes
enable local email testing for the CNP assignment, improving
development efficiency.
---
CNP/Wireshark/SMTP/mail-sender.py | 14 +++++++++++++
CNP/Wireshark/SMTP/smtp-server.py | 33 +++++++++++++++++++++++++++++++
2 files changed, 47 insertions(+)
create mode 100644 CNP/Wireshark/SMTP/mail-sender.py
create mode 100644 CNP/Wireshark/SMTP/smtp-server.py
diff --git a/CNP/Wireshark/SMTP/mail-sender.py b/CNP/Wireshark/SMTP/mail-sender.py
new file mode 100644
index 0000000..186f05e
--- /dev/null
+++ b/CNP/Wireshark/SMTP/mail-sender.py
@@ -0,0 +1,14 @@
+import smtplib
+from email.message import EmailMessage
+
+# the email message
+msg = EmailMessage()
+msg['Subject'] = 'CNP Assignment Email'
+msg['From'] = 'aadit@example.com'
+msg['To'] = 'shreyas@example.com' # used example.com just to not have a DNS error.
+msg.set_content('Hello World. This is a message that is to be captured for the CNP FISAC II.')
+
+#SMTP server running on localhost on port 25
+with smtplib.SMTP('127.0.0.1', 25) as server:
+ server.set_debuglevel(1) # debug output to see the SMTP conversation (for dev log)
+ server.send_message(msg)
diff --git a/CNP/Wireshark/SMTP/smtp-server.py b/CNP/Wireshark/SMTP/smtp-server.py
new file mode 100644
index 0000000..1868743
--- /dev/null
+++ b/CNP/Wireshark/SMTP/smtp-server.py
@@ -0,0 +1,33 @@
+import asyncio
+import uvloop
+from aiosmtpd.controller import Controller
+
+# handler that just prints the message content
+class PrintHandler:
+ async def handle_DATA(self, server, session, envelope):
+ print("Message from:", envelope.mail_from)
+ print("Recipients:", envelope.rcpt_tos)
+ print("Message data:")
+ print(envelope.content.decode('utf8', errors='replace'))
+ print("End of message")
+ # Respond with a success code
+ return '250 Message accepted for delivery'
+
+# uvloop for better performance
+asyncio.set_event_loop_policy(uvloop.EventLoopPolicy())
+
+def run_server():
+ # SMTP server controller, binding to localhost on port 25
+ controller = Controller(PrintHandler(), hostname='127.0.0.1', port=25)
+ controller.start()
+ print("SMTP server running on port 25. Press Ctrl+C to stop.")
+ try:
+ # Run forever
+ asyncio.get_event_loop().run_forever()
+ except KeyboardInterrupt:
+ pass
+ finally:
+ controller.stop()
+
+if __name__ == '__main__':
+ run_server()