feat: implement SMTP server with authentication, port validation, and email storage

1 files changed, 100 insertions, 1 deletions

diff --git a/example.config.toml b/example.config.toml
index 8748a3b..be3cdaf 100644
--- a/example.config.toml
+++ b/example.config.toml
@@ -1,22 +1,77 @@
+# =============================================================================
+# Dove - Local SMTP Email Testing Tool
+# =============================================================================
+# Copy this file to config.toml and adjust values as needed.
+# All values shown below are defaults and can be omitted if unchanged.
+
+# -----------------------------------------------------------------------------
+# HTTP Server
+# -----------------------------------------------------------------------------
+# The web dashboard for viewing and managing captured emails.
+
 [server]
+# Network interface to bind the HTTP server to.
+# Use "0.0.0.0" to listen on all interfaces, or "127.0.0.1" for local only.
 host = "0.0.0.0"
+
+# Port for the web dashboard.
 port = 8080
+
+# Enable verbose debug logging for HTTP requests.
 debug = false
+
+# Optional credentials to protect the web dashboard.
+# Leave commented out to disable dashboard authentication.
 # username = ""
 # password = ""
 
+# -----------------------------------------------------------------------------
+# SMTP Server
+# -----------------------------------------------------------------------------
+# Receives incoming emails from mail clients and applications.
+
 [smtp]
+# Network interface to bind the SMTP server to.
 host = "0.0.0.0"
+
+# Port for plain SMTP connections.
 port = 5025
+
+# Port for implicit TLS (SMTPS) connections. Requires tls_enabled = true.
 smtps_port = 5465
+
+# Port for STARTTLS connections. Requires tls_enabled = true.
 starttls_port = 5587
+
+# The domain name announced in SMTP EHLO/HELO greetings.
+# This identifies the mail server to connecting clients.
+domain = "localhost"
+
+# Maximum allowed email size in bytes (default: 25 MB).
 max_message_size = 26214400
+
+# Timeout in seconds for reading data from SMTP clients.
+read_timeout = 30
+
+# Timeout in seconds for writing data to SMTP clients.
+write_timeout = 30
+
+# Require SMTP authentication before accepting messages.
 auth_required = false
+
+# Credentials for SMTP authentication. Only used when auth_required = true.
 # username = ""
 # password = ""
+
+# Enable TLS support for SMTPS and STARTTLS listeners.
 tls_enabled = false
+
+# Paths to TLS certificate and private key files. Required when tls_enabled = true.
 # tls_cert = ""
 # tls_key = ""
+
+# Relay captured emails to an upstream SMTP server.
+# Useful for forwarding test emails to a real mail server.
 relay_enabled = false
 # relay_host = ""
 relay_port = 587
@@ -24,27 +79,71 @@ relay_port = 587
 # relay_password = ""
 relay_starttls = true
 
+# -----------------------------------------------------------------------------
+# IMAP Server
+# -----------------------------------------------------------------------------
+# Allows mail clients to retrieve captured emails via the IMAP protocol.
+
 [imap]
+# Network interface to bind the IMAP server to.
 host = "0.0.0.0"
+
+# Port for plain IMAP connections.
 port = 5143
+
+# Port for implicit TLS (IMAPS) connections. Requires tls_enabled = true.
 imaps_port = 5993
+
+# Require IMAP authentication before granting access.
 auth_required = false
+
+# Credentials for IMAP authentication. Only used when auth_required = true.
 # username = ""
 # password = ""
+
+# Enable TLS support for the IMAPS listener.
 tls_enabled = false
+
+# Paths to TLS certificate and private key files. Required when tls_enabled = true.
 # tls_cert = ""
 # tls_key = ""
 
+# -----------------------------------------------------------------------------
+# POP3 Server
+# -----------------------------------------------------------------------------
+# Allows mail clients to retrieve captured emails via the POP3 protocol.
+
 [pop3]
+# Network interface to bind the POP3 server to.
 host = "0.0.0.0"
+
+# Port for plain POP3 connections.
 port = 5110
+
+# Port for implicit TLS (POP3S) connections. Requires tls_enabled = true.
 pop3s_port = 5995
+
+# Require POP3 authentication before granting access.
 auth_required = false
+
+# Credentials for POP3 authentication. Only used when auth_required = true.
 # username = ""
 # password = ""
+
+# Enable TLS support for the POP3S listener.
 tls_enabled = false
+
+# Paths to TLS certificate and private key files. Required when tls_enabled = true.
 # tls_cert = ""
 # tls_key = ""
 
+# -----------------------------------------------------------------------------
+# Mailbox
+# -----------------------------------------------------------------------------
+# Controls how incoming emails are routed to mailboxes.
+
 [mailbox]
-mode = "registered"
\ No newline at end of file
+# Mailbox routing mode:
+#   "registered" - Only accept emails for registered mailbox addresses.
+#   "open"       - Automatically create mailboxes for any recipient address.
+mode = "registered"