diff --git a/include/metalsvm/config.h.example b/include/metalsvm/config.h.example
index 783461f1..14710be2 100644
--- a/include/metalsvm/config.h.example
+++ b/include/metalsvm/config.h.example
@@ -30,6 +30,7 @@ extern "C" {
 #define DEFAULT_STACK_SIZE 	(32*1024)
 #define KMSG_SIZE		(1024*1024)
 #define PAGE_SIZE		4096
+#define MAILBOX_SIZE		2
 #define TIMER_FREQ		100	/* in HZ */
 #define CLOCK_TICK_RATE		1193182	/* 8254 chip's internal oscillator frequency */
 
diff --git a/include/metalsvm/mailbox.h b/include/metalsvm/mailbox.h
index 0179b5a5..30027503 100644
--- a/include/metalsvm/mailbox.h
+++ b/include/metalsvm/mailbox.h
@@ -29,17 +29,20 @@ extern "C" {
 #endif
 
 typedef struct {
-	void* mail;
-	sem_t consume, produce;
+	void* buffer[MAILBOX_SIZE];
+	int wpos, rpos;
+	sem_t mails;
+	sem_t boxes;
 } mailbox_t;
 
 inline static int mailbox_init(mailbox_t* m) {
 	if (BUILTIN_EXPECT(!m, 0))
 		return -1;
 
-	m->mail = NULL;
-	sem_init(&m->consume, 0);
-	sem_init(&m->produce, 1);
+	memset(m->buffer, 0x00, sizeof(void*)*MAILBOX_SIZE);
+	m->wpos = m->rpos = 0;
+	sem_init(&m->mails, 0);
+	sem_init(&m->boxes, MAILBOX_SIZE);
 
 	return 0;
 }
@@ -48,8 +51,8 @@ inline static int mailbox_destroy(mailbox_t* m) {
 	if (BUILTIN_EXPECT(!m, 0))
 		return -1;
 
-	sem_destroy(&m->consume);
-	sem_destroy(&m->produce);
+	sem_destroy(&m->mails);
+	sem_destroy(&m->boxes);
 
 	return 0;
 }
@@ -58,9 +61,10 @@ inline static int mailbox_post(mailbox_t* m, void* mail) {
 	if (BUILTIN_EXPECT(!m, 0))
 		return -1;
 
-	sem_wait(&m->produce);
-	m->mail = mail;
-	sem_post(&m->consume);
+	sem_wait(&m->boxes);
+	m->buffer[m->wpos] = mail;
+	m->wpos = (m->wpos+1) % MAILBOX_SIZE;
+	sem_post(&m->mails);
 
 	return 0;
 }
@@ -69,10 +73,11 @@ inline static int mailbox_fetch(mailbox_t* m, void** mail) {
 	if (BUILTIN_EXPECT(!m || !mail, 0))
 		return -1;
 
-        sem_wait(&m->consume);
-        *mail = m->mail;
-	m->mail = NULL;
-        sem_post(&m->produce);
+        sem_wait(&m->mails);
+	*mail = m->buffer[m->rpos];
+	m->buffer[m->rpos] = NULL;
+	m->rpos = (m->rpos+1) % MAILBOX_SIZE;
+        sem_post(&m->boxes);
 
 	return 0;
 }
@@ -81,11 +86,12 @@ inline static int mailbox_tryfetch(mailbox_t* m, void** mail) {
 	if (BUILTIN_EXPECT(!m || !mail, 0))
 		return -1;
 
-	if (sem_trywait(&m->consume) != 0)
+	if (sem_trywait(&m->mails) != 0)
 		return -1;
-        *mail = m->mail;
-	m->mail = NULL;
-        sem_post(&m->produce);
+        *mail = m->buffer[m->rpos];
+	m->buffer[m->rpos] = NULL;
+	m->rpos = (m->rpos+1) % MAILBOX_SIZE;
+        sem_post(&m->boxes);
 
         return 0;
 }