diff --git a/services.conf b/services.conf
new file mode 100644
index 0000000..66d7c5f
--- /dev/null
+++ b/services.conf
@@ -0,0 +1,14 @@
+# Service Monitor - Configuración
+# ================================
+
+# Servicios HTTP
+http,Forgejo (HTTP),https://git.reugenio.com
+http,Simifactu API,https://simifactu.com
+http,Mundisofa,https://mundisofa.com
+http,Menzuri,https://menzuri.com
+
+# Servicios TCP
+tcp,Forgejo (SSH),git.reugenio.com,2222
+
+# Telegram
+telegram,8158165444:AAFxUjLChsuusgFD5B1gt2svt8NflvAm1M8,1481345275
diff --git a/src/main.zig b/src/main.zig
index 74a5dd0..187fee5 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -16,6 +16,8 @@ const tcp = @import("tcp.zig");
 const config = @import("config.zig");
 const notify = @import("notify.zig");
 const daemon = @import("daemon.zig");
+const smtp = @import("smtp.zig");
+const telegram = @import("telegram.zig");
 
 /// Archivo de log por defecto.
 const DEFAULT_LOG_FILE = "service-monitor.log";
@@ -128,12 +130,12 @@ pub fn main() !void {
         }
 
         while (true) {
-            _ = try runChecks(allocator, output_writer, log_file, options.notify, cfg.services);
+            _ = try runChecks(allocator, output_writer, log_file, options.notify, &cfg);
             std.time.sleep(@as(u64, options.interval_seconds) * std.time.ns_per_s);
         }
     } else {
         try stdout.print("\n=== Service Monitor ===\n\n", .{});
-        const had_errors = try runChecks(allocator, stdout, log_file, options.notify, cfg.services);
+        const had_errors = try runChecks(allocator, stdout, log_file, options.notify, &cfg);
 
         if (had_errors) {
             std.process.exit(1);
@@ -147,11 +149,12 @@ fn runChecks(
     stdout: ?std.fs.File.Writer,
     log_file: ?std.fs.File,
     notify_enabled: bool,
-    services: []const config.Service,
+    cfg: *const config.Config,
 ) !bool {
     var had_errors = false;
     var error_count: u32 = 0;
     var error_services: [16][]const u8 = undefined;
+    const services = cfg.services;
 
     // Timestamp
     const timestamp = std.time.timestamp();
@@ -237,6 +240,54 @@ fn runChecks(
         notify.send(allocator, "⚠️ Servicios caídos", body_buf[0..body_len], "critical") catch {};
     }
 
+    // Enviar email si hay configuración SMTP y destinatarios
+    if (had_errors and cfg.smtp.host.len > 0 and cfg.email_recipients.len > 0) {
+        var body_buf: [1024]u8 = undefined;
+        var body_len: usize = 0;
+
+        // Construir cuerpo del email
+        const header = "Los siguientes servicios no responden:\n\n";
+        @memcpy(body_buf[0..header.len], header);
+        body_len = header.len;
+
+        for (error_services[0..error_count]) |svc_name| {
+            if (body_len + svc_name.len + 3 < body_buf.len) {
+                body_buf[body_len] = '-';
+                body_buf[body_len + 1] = ' ';
+                body_len += 2;
+                @memcpy(body_buf[body_len..][0..svc_name.len], svc_name);
+                body_len += svc_name.len;
+                body_buf[body_len] = '\n';
+                body_len += 1;
+            }
+        }
+
+        smtp.sendEmail(allocator, .{
+            .host = cfg.smtp.host,
+            .port = cfg.smtp.port,
+            .username = cfg.smtp.username,
+            .password = cfg.smtp.password,
+            .from = if (cfg.smtp.from.len > 0) cfg.smtp.from else cfg.smtp.username,
+            .to = cfg.email_recipients,
+            .subject = "[Service Monitor] Alerta: Servicios caídos",
+            .body = body_buf[0..body_len],
+        }) catch {
+            // Ignorar errores de email, no son críticos
+        };
+    }
+
+    // Enviar Telegram si hay configuración
+    if (had_errors and cfg.telegram.bot_token.len > 0 and cfg.telegram.chat_id.len > 0) {
+        telegram.sendAlert(
+            allocator,
+            cfg.telegram.bot_token,
+            cfg.telegram.chat_id,
+            error_services[0..error_count],
+        ) catch {
+            // Ignorar errores de Telegram, no son críticos
+        };
+    }
+
     return had_errors;
 }
 
diff --git a/src/smtp.zig b/src/smtp.zig
new file mode 100644
index 0000000..bca4ba7
--- /dev/null
+++ b/src/smtp.zig
@@ -0,0 +1,261 @@
+//! Cliente SMTP para envío de emails
+//!
+//! Implementación del protocolo SMTP (RFC 5321) con soporte para
+//! autenticación AUTH LOGIN y STARTTLS.
+//!
+//! Ejemplo de uso:
+//! ```zig
+//! try smtp.sendEmail(allocator, .{
+//!     .host = "smtp.gmail.com",
+//!     .port = 587,
+//!     .username = "usuario@gmail.com",
+//!     .password = "app_password",
+//!     .from = "usuario@gmail.com",
+//!     .to = &[_][]const u8{"destino@ejemplo.com"},
+//!     .subject = "Alerta",
+//!     .body = "Servicio caído",
+//! });
+//! ```
+
+const std = @import("std");
+
+/// Errores posibles durante el envío SMTP.
+pub const SmtpError = error{
+    /// No se pudo conectar al servidor SMTP.
+    ConnectionFailed,
+    /// El servidor cerró la conexión inesperadamente.
+    ConnectionClosed,
+    /// Respuesta inesperada del servidor.
+    UnexpectedResponse,
+    /// Fallo en autenticación.
+    AuthenticationFailed,
+    /// El servidor rechazó el remitente.
+    SenderRejected,
+    /// El servidor rechazó el destinatario.
+    RecipientRejected,
+    /// Error enviando el mensaje.
+    MessageRejected,
+    /// Timeout esperando respuesta.
+    Timeout,
+    /// Error de red.
+    NetworkError,
+    /// Buffer demasiado pequeño.
+    BufferTooSmall,
+};
+
+/// Opciones para enviar un email.
+pub const EmailOptions = struct {
+    /// Servidor SMTP.
+    host: []const u8,
+    /// Puerto (25, 465, 587).
+    port: u16 = 587,
+    /// Usuario para autenticación.
+    username: []const u8 = "",
+    /// Contraseña para autenticación.
+    password: []const u8 = "",
+    /// Dirección del remitente.
+    from: []const u8,
+    /// Direcciones de destinatarios.
+    to: []const []const u8,
+    /// Asunto del email.
+    subject: []const u8,
+    /// Cuerpo del email (texto plano).
+    body: []const u8,
+};
+
+/// Envía un email usando SMTP.
+///
+/// Soporta autenticación AUTH LOGIN. Para servidores que requieren
+/// TLS (como Gmail en puerto 587), se necesita STARTTLS que aún
+/// no está implementado - usar puerto 465 (SMTPS) como alternativa.
+pub fn sendEmail(allocator: std.mem.Allocator, options: EmailOptions) SmtpError!void {
+    // Conectar al servidor
+    const stream = std.net.tcpConnectToHost(allocator, options.host, options.port) catch {
+        return SmtpError.ConnectionFailed;
+    };
+    defer stream.close();
+
+    var read_buffer: [1024]u8 = undefined;
+
+    // Recibir saludo (220)
+    try expectResponse(stream, &read_buffer, "220");
+
+    // EHLO
+    try sendCommand(stream, "EHLO localhost\r\n");
+    try expectResponse(stream, &read_buffer, "250");
+
+    // Autenticación si hay credenciales
+    if (options.username.len > 0 and options.password.len > 0) {
+        try sendCommand(stream, "AUTH LOGIN\r\n");
+        try expectResponse(stream, &read_buffer, "334");
+
+        // Usuario en Base64
+        var user_b64: [256]u8 = undefined;
+        const user_encoded = base64Encode(options.username, &user_b64) catch {
+            return SmtpError.BufferTooSmall;
+        };
+        try sendLine(stream, user_encoded);
+        try expectResponse(stream, &read_buffer, "334");
+
+        // Password en Base64
+        var pass_b64: [256]u8 = undefined;
+        const pass_encoded = base64Encode(options.password, &pass_b64) catch {
+            return SmtpError.BufferTooSmall;
+        };
+        try sendLine(stream, pass_encoded);
+
+        const auth_response = try readResponse(stream, &read_buffer);
+        if (!std.mem.startsWith(u8, auth_response, "235")) {
+            return SmtpError.AuthenticationFailed;
+        }
+    }
+
+    // MAIL FROM
+    var from_cmd: [512]u8 = undefined;
+    const from_len = std.fmt.bufPrint(&from_cmd, "MAIL FROM:<{s}>\r\n", .{options.from}) catch {
+        return SmtpError.BufferTooSmall;
+    };
+    try sendCommand(stream, from_len);
+
+    const from_response = try readResponse(stream, &read_buffer);
+    if (!std.mem.startsWith(u8, from_response, "250")) {
+        return SmtpError.SenderRejected;
+    }
+
+    // RCPT TO (para cada destinatario)
+    for (options.to) |recipient| {
+        var rcpt_cmd: [512]u8 = undefined;
+        const rcpt_len = std.fmt.bufPrint(&rcpt_cmd, "RCPT TO:<{s}>\r\n", .{recipient}) catch {
+            return SmtpError.BufferTooSmall;
+        };
+        try sendCommand(stream, rcpt_len);
+
+        const rcpt_response = try readResponse(stream, &read_buffer);
+        if (!std.mem.startsWith(u8, rcpt_response, "250")) {
+            return SmtpError.RecipientRejected;
+        }
+    }
+
+    // DATA
+    try sendCommand(stream, "DATA\r\n");
+    try expectResponse(stream, &read_buffer, "354");
+
+    // Headers + Body
+    var msg_buffer: [4096]u8 = undefined;
+    const msg = std.fmt.bufPrint(&msg_buffer,
+        \\From: {s}
+        \\To: {s}
+        \\Subject: {s}
+        \\Content-Type: text/plain; charset=UTF-8
+        \\
+        \\{s}
+        \\.
+        \\
+    , .{
+        options.from,
+        options.to[0], // Primer destinatario en header
+        options.subject,
+        options.body,
+    }) catch {
+        return SmtpError.BufferTooSmall;
+    };
+
+    // Convertir \n a \r\n para SMTP
+    try sendSmtpData(stream, msg);
+
+    const data_response = try readResponse(stream, &read_buffer);
+    if (!std.mem.startsWith(u8, data_response, "250")) {
+        return SmtpError.MessageRejected;
+    }
+
+    // QUIT
+    try sendCommand(stream, "QUIT\r\n");
+    // No esperamos respuesta de QUIT, solo cerramos
+}
+
+/// Lee una respuesta del servidor SMTP.
+fn readResponse(stream: std.net.Stream, buffer: []u8) SmtpError![]const u8 {
+    const bytes_read = stream.read(buffer) catch {
+        return SmtpError.NetworkError;
+    };
+
+    if (bytes_read == 0) {
+        return SmtpError.ConnectionClosed;
+    }
+
+    return buffer[0..bytes_read];
+}
+
+/// Espera una respuesta que empiece con el código dado.
+fn expectResponse(stream: std.net.Stream, buffer: []u8, expected_code: []const u8) SmtpError!void {
+    const response = try readResponse(stream, buffer);
+
+    if (!std.mem.startsWith(u8, response, expected_code)) {
+        return SmtpError.UnexpectedResponse;
+    }
+}
+
+/// Envía un comando al servidor.
+fn sendCommand(stream: std.net.Stream, command: []const u8) SmtpError!void {
+    _ = stream.write(command) catch {
+        return SmtpError.NetworkError;
+    };
+}
+
+/// Envía una línea con CRLF al final.
+fn sendLine(stream: std.net.Stream, line: []const u8) SmtpError!void {
+    _ = stream.write(line) catch {
+        return SmtpError.NetworkError;
+    };
+    _ = stream.write("\r\n") catch {
+        return SmtpError.NetworkError;
+    };
+}
+
+/// Envía datos SMTP convirtiendo \n a \r\n.
+fn sendSmtpData(stream: std.net.Stream, data: []const u8) SmtpError!void {
+    var i: usize = 0;
+    while (i < data.len) {
+        const start = i;
+        // Buscar siguiente \n
+        while (i < data.len and data[i] != '\n') : (i += 1) {}
+
+        // Enviar hasta aquí
+        if (i > start) {
+            _ = stream.write(data[start..i]) catch {
+                return SmtpError.NetworkError;
+            };
+        }
+
+        // Si encontramos \n, enviar \r\n
+        if (i < data.len and data[i] == '\n') {
+            _ = stream.write("\r\n") catch {
+                return SmtpError.NetworkError;
+            };
+            i += 1;
+        }
+    }
+}
+
+/// Codifica datos en Base64.
+fn base64Encode(input: []const u8, output: []u8) ![]const u8 {
+    const encoder = std.base64.standard.Encoder;
+    const encoded_len = encoder.calcSize(input.len);
+
+    if (encoded_len > output.len) {
+        return error.BufferTooSmall;
+    }
+
+    const result = encoder.encode(output, input);
+    return result;
+}
+
+// ============================================================================
+// Tests
+// ============================================================================
+
+test "base64 encode" {
+    var buffer: [64]u8 = undefined;
+    const result = try base64Encode("test", &buffer);
+    try std.testing.expectEqualStrings("dGVzdA==", result);
+}
diff --git a/src/telegram.zig b/src/telegram.zig
new file mode 100644
index 0000000..7e7d94a
--- /dev/null
+++ b/src/telegram.zig
@@ -0,0 +1,106 @@
+//! Cliente Telegram Bot API
+//!
+//! Envía mensajes a través de la API de bots de Telegram.
+//! Usa curl para las peticiones HTTP (más fiable que std.http para POST).
+//!
+//! Para obtener los valores necesarios:
+//! 1. Habla con @BotFather en Telegram para crear un bot y obtener el token
+//! 2. Habla con @userinfobot para obtener tu chat_id
+//!
+//! Ejemplo:
+//! ```zig
+//! try telegram.sendMessage(allocator, "123:ABC", "987654321", "Servicio caído!");
+//! ```
+
+const std = @import("std");
+
+/// Errores posibles durante el envío.
+pub const TelegramError = error{
+    /// No se pudo ejecutar curl.
+    CommandFailed,
+    /// La API rechazó la petición.
+    ApiError,
+};
+
+/// Envía un mensaje de texto a través de Telegram Bot API.
+///
+/// Usa curl para la petición HTTP POST (más fiable para JSON).
+pub fn sendMessage(
+    allocator: std.mem.Allocator,
+    bot_token: []const u8,
+    chat_id: []const u8,
+    message: []const u8,
+) TelegramError!void {
+    // Construir URL
+    var url_buf: [256]u8 = undefined;
+    const url = std.fmt.bufPrint(&url_buf, "https://api.telegram.org/bot{s}/sendMessage", .{bot_token}) catch {
+        return TelegramError.CommandFailed;
+    };
+
+    // Construir JSON body
+    var body_buf: [2048]u8 = undefined;
+    const body = std.fmt.bufPrint(&body_buf,
+        \\{{"chat_id":"{s}","text":"{s}"}}
+    , .{ chat_id, message }) catch {
+        return TelegramError.CommandFailed;
+    };
+
+    // Ejecutar curl
+    const result = std.process.Child.run(.{
+        .allocator = allocator,
+        .argv = &[_][]const u8{
+            "curl",
+            "-s",
+            "-X",
+            "POST",
+            url,
+            "-H",
+            "Content-Type: application/json",
+            "-d",
+            body,
+        },
+    }) catch {
+        return TelegramError.CommandFailed;
+    };
+
+    allocator.free(result.stdout);
+    allocator.free(result.stderr);
+
+    if (result.term.Exited != 0) {
+        return TelegramError.CommandFailed;
+    }
+}
+
+/// Envía una alerta formateada sobre servicios caídos.
+pub fn sendAlert(
+    allocator: std.mem.Allocator,
+    bot_token: []const u8,
+    chat_id: []const u8,
+    failed_services: []const []const u8,
+) TelegramError!void {
+    var msg_buf: [1024]u8 = undefined;
+    var msg_len: usize = 0;
+
+    // Header
+    const header = "⚠️ ALERTA: Servicios caídos\\n\\n";
+    @memcpy(msg_buf[0..header.len], header);
+    msg_len = header.len;
+
+    // Lista de servicios
+    for (failed_services) |service| {
+        if (msg_len + service.len + 6 < msg_buf.len) {
+            // "• "
+            msg_buf[msg_len] = '-';
+            msg_buf[msg_len + 1] = ' ';
+            msg_len += 2;
+            @memcpy(msg_buf[msg_len..][0..service.len], service);
+            msg_len += service.len;
+            // "\n" escapado para JSON
+            msg_buf[msg_len] = '\\';
+            msg_buf[msg_len + 1] = 'n';
+            msg_len += 2;
+        }
+    }
+
+    return sendMessage(allocator, bot_token, chat_id, msg_buf[0..msg_len]);
+}