diff --git a/model.sql b/model.sql
index 060f916..b583609 100644
--- a/model.sql
+++ b/model.sql
@@ -1,7 +1,6 @@
 begin;
 DROP TABLE correos.destinatarios;
 DROP TABLE correos.cartas;
---DROP TABLE correos.origenes;
 DROP TABLE correos.direcciones;
 DROP TABLE correos.mxrecords;
 DROP TABLE correos.arecords;
@@ -9,8 +8,6 @@ DROP TABLE correos.ipv4addrs;
 DROP TABLE correos.fqdns;
 
 DROP SCHEMA correos;
-
-
 CREATE SCHEMA correos;
 
 CREATE TABLE correos.fqdns (
@@ -34,7 +31,7 @@ CREATE TABLE correos.direcciones (
 	nombre VARCHAR, 
 	PRIMARY KEY (id), 
 	UNIQUE (direccion), 
-	FOREIGN KEY(dominioid) REFERENCES correos.fqdns (id)
+	FOREIGN KEY(dominioid) REFERENCES correos.fqdns (id)  ON DELETE CASCADE ON UPDATE CASCADE
 );
 
 CREATE TABLE correos.mxrecords (
@@ -44,7 +41,7 @@ CREATE TABLE correos.mxrecords (
 	prioridad INTEGER DEFAULT 10000, 
 	validohasta INTEGER DEFAULT 0, 
 	PRIMARY KEY (id), 
-	FOREIGN KEY(fqdnid) REFERENCES correos.fqdns (id)
+	FOREIGN KEY(fqdnid) REFERENCES correos.fqdns (id)  ON DELETE CASCADE ON UPDATE CASCADE
 );
 
 CREATE TABLE correos.arecords (
@@ -57,8 +54,8 @@ CREATE TABLE correos.arecords (
 	sesiones INTEGER DEFAULT 0, 
 	validohasta INTEGER DEFAULT 0, 
 	PRIMARY KEY (id), 
-	FOREIGN KEY(fqdnid) REFERENCES correos.fqdns (id), 
-	FOREIGN KEY(ipv4id) REFERENCES correos.ipv4addrs (id)
+	FOREIGN KEY(fqdnid) REFERENCES correos.fqdns (id) ON DELETE CASCADE ON UPDATE CASCADE, 
+	FOREIGN KEY(ipv4id) REFERENCES correos.ipv4addrs (id) ON DELETE CASCADE ON UPDATE CASCADE
 );
 
 CREATE TABLE correos.cartas (
@@ -67,7 +64,7 @@ CREATE TABLE correos.cartas (
 	contenido TEXT, 
 	recibido TIMESTAMP WITH TIME ZONE, 
 	PRIMARY KEY (id), 
-	FOREIGN KEY(remitenteid) REFERENCES correos.direcciones (id)
+	FOREIGN KEY(remitenteid) REFERENCES correos.direcciones (id) ON DELETE CASCADE ON UPDATE CASCADE
 );
 
 CREATE TABLE correos.destinatarios (
@@ -78,7 +75,7 @@ CREATE TABLE correos.destinatarios (
 	intentos INTEGER DEFAULT 0, 
 	timestamp TIMESTAMP WITH TIME ZONE, 
 	PRIMARY KEY (id), 
-	FOREIGN KEY(direccionid) REFERENCES correos.direcciones (id), 
-	FOREIGN KEY(cartaid) REFERENCES correos.cartas (id)
+	FOREIGN KEY(direccionid) REFERENCES correos.direcciones (id) ON DELETE CASCADE ON UPDATE CASCADE, 
+	FOREIGN KEY(cartaid) REFERENCES correos.cartas (id) ON DELETE CASCADE ON UPDATE CASCADE
 );
 commit;
\ No newline at end of file
diff --git a/sender.py b/sender.py
index eb592ed..a2c1aae 100644
--- a/sender.py
+++ b/sender.py
@@ -4,18 +4,23 @@ import time
 import signal
 import asyncio
 
+if not os.environ.get('HEARTBEAT'):
+	hb = 60 * 15 # 15 minutos
+else:
+	hb = int(os.environ.get('HEARTBEAT'))
+
 def main():
 
 	async def main_loop():
 		await log.info('Demonio iniciado')
-		doki = int(time.time()) + 60
+		doki = int(time.time()) + hb
 		while True:
 			if 	await pre_process():
 				await enviaCorreos()
 			await asyncio.sleep(10)
 			i = int(time.time())
 			if i >= doki:
-				doki = i + 60
+				doki = i + hb
 				await log.info('Heartbeat')
 	
 	def run():
diff --git a/server.py b/server.py
index 83d076d..4d82792 100644
--- a/server.py
+++ b/server.py
@@ -4,18 +4,24 @@ import time
 import signal
 import asyncio
 
+
+if not os.environ.get('HEARTBEAT'):
+	hb = 60 * 15 # 15 minutos
+else:
+	hb = int(os.environ.get('HEARTBEAT'))
+
 def main():
 
 	mayordomo = create_async_smtp_server()
 	
 	async def main_loop():
 		await log.info('Demonio iniciado')
-		doki=int(time.time()) + 60
+		doki=int(time.time()) + hb
 		while True:
 			await asyncio.sleep(1)
 			i = int(time.time())
 			if i >= doki:
-				doki = i + 60
+				doki = i + hb
 				await log.info('Heartbeat')
 	
 	def run():