diff --git a/etc/example.conf b/etc/example.conf
index fc24e48..9c6adfd 100644
--- a/etc/example.conf
+++ b/etc/example.conf
@@ -7,6 +7,11 @@
 ; 5: debug
 verbosity=1
 
+; unique server id. If you have more than 1 piler hosts combined,
+; then assign a unique value to each host. Possible values: 0-255
+server_id=0
+
+
 ; piler daemon will use this user (and its group)
 ; it it was started by root
 username=piler
diff --git a/src/cfg.c b/src/cfg.c
index d7d5f17..2792bf7 100644
--- a/src/cfg.c
+++ b/src/cfg.c
@@ -91,6 +91,7 @@
    { "pidfile", "string", (void*) string_parser, offsetof(struct __config, pidfile), PIDFILE, MAXVAL-1},
    { "piler_header_field", "string", (void*) string_parser, offsetof(struct __config, piler_header_field), "", MAXVAL-1},
    { "queuedir", "string", (void*) string_parser, offsetof(struct __config, queuedir), QUEUE_DIR, MAXVAL-1},
+   { "server_id", "integer", (void*) int_parser, offsetof(struct __config, server_id), "0", sizeof(int)},
    { "session_timeout", "integer", (void*) int_parser, offsetof(struct __config, session_timeout), "420", sizeof(int)},
    { "spam_header_line", "string", (void*) string_parser, offsetof(struct __config, spam_header_line), "", MAXVAL-1},
    { "tls_enable", "integer", (void*) int_parser, offsetof(struct __config, tls_enable), "0", sizeof(int)},
diff --git a/src/cfg.h b/src/cfg.h
index fcc403a..3c12789 100644
--- a/src/cfg.h
+++ b/src/cfg.h
@@ -8,6 +8,7 @@
 #include "config.h"
 
 struct __config {
+   int server_id;
    char username[MAXVAL];
 
    char hostid[MAXVAL];
diff --git a/src/import.c b/src/import.c
index b972b3b..e271289 100644
--- a/src/import.c
+++ b/src/import.c
@@ -26,7 +26,7 @@
    struct __counters counters;
 
 
-   init_session_data(sdata);
+   init_session_data(sdata, cfg->server_id);
 
    if(cfg->verbosity > 1) printf("processing: %s\n", filename);
 
diff --git a/src/misc.c b/src/misc.c
index 98f9dd3..a7702ab 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -211,13 +211,13 @@
 }
 
 
-void create_id(char *id){
+void create_id(char *id, unsigned char server_id){
    int i;
    unsigned char buf[RND_STR_LEN/2];
 
    memset(id, 0, SMALLBUFSIZE);
 
-   get_random_bytes(buf, RND_STR_LEN/2);
+   get_random_bytes(buf, RND_STR_LEN/2, server_id);
 
    for(i=0; i < RND_STR_LEN/2; i++){
       sprintf(id, "%02x", buf[i]);
@@ -231,7 +231,7 @@
  * reading from pool
  */
 
-int get_random_bytes(unsigned char *buf, int len){
+int get_random_bytes(unsigned char *buf, int len, unsigned char server_id){
    int fd, ret=0;
    struct taia now;
    char nowpack[TAIA_PACK];
@@ -246,7 +246,9 @@
    fd = open(RANDOM_POOL, O_RDONLY);
    if(fd == -1) return ret;
 
-   if(readFromEntropyPool(fd, buf+12, len-12) != len-12){
+   *(buf + 12) = server_id;
+
+   if(readFromEntropyPool(fd, buf+12+1, len-12-1) != len-12-1){
       syslog(LOG_PRIORITY, "%s: %s", ERR_CANNOT_READ_FROM_POOL, RANDOM_POOL);
    }
    
@@ -447,13 +449,13 @@
 }
 
 
-void init_session_data(struct session_data *sdata){
+void init_session_data(struct session_data *sdata, unsigned char server_id){
    int i;
 
 
    sdata->fd = -1;
 
-   create_id(&(sdata->ttmpfile[0]));
+   create_id(&(sdata->ttmpfile[0]), server_id);
    unlink(sdata->ttmpfile);
 
    snprintf(sdata->filename, SMALLBUFSIZE-1, "%s", sdata->ttmpfile);
diff --git a/src/misc.h b/src/misc.h
index 28167bb..4732333 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -24,8 +24,8 @@
 char *split_str(char *row, char *what, char *s, int size);
 int trimBuffer(char *s);
 int extractEmail(char *rawmail, char *email);
-void create_id(char *id);
-int get_random_bytes(unsigned char *buf, int len);
+void create_id(char *id, unsigned char server_id);
+int get_random_bytes(unsigned char *buf, int len, unsigned char server_id);
 int readFromEntropyPool(int fd, void *_s, size_t n);
 int recvtimeout(int s, char *buf, int len, int timeout);
 int write1(int sd, char *buf, int use_ssl, SSL *ssl);
@@ -35,7 +35,7 @@
 int drop_privileges(struct passwd *pwd);
 
 int is_email_address_on_my_domains(char *email, struct __config *cfg);
-void init_session_data(struct session_data *sdata);
+void init_session_data(struct session_data *sdata, unsigned char server_id);
 int read_from_stdin(struct session_data *sdata);
 void strtolower(char *s);
 
diff --git a/src/pilerexport.c b/src/pilerexport.c
index fc45ed5..196a72b 100644
--- a/src/pilerexport.c
+++ b/src/pilerexport.c
@@ -400,7 +400,7 @@
    if(read_key(&cfg)) p_clean_exit(ERR_READING_KEY, 1);
 
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg.server_id);
 
 
    mysql_init(&(sdata.mysql));
diff --git a/src/pilerpurge.c b/src/pilerpurge.c
index b74222e..1197edc 100644
--- a/src/pilerpurge.c
+++ b/src/pilerpurge.c
@@ -348,7 +348,7 @@
 
    setlocale(LC_CTYPE, cfg.locale);
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg.server_id);
 
    i = is_purge_allowed(&sdata, &cfg);
    if(i == 1){
diff --git a/src/reindex.c b/src/reindex.c
index 66fdccc..a255d26 100644
--- a/src/reindex.c
+++ b/src/reindex.c
@@ -212,7 +212,7 @@
       }
    }
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg.server_id);
 
 
    mysql_init(&(sdata.mysql));
diff --git a/src/session.c b/src/session.c
index 4a146de..d1937f3 100644
--- a/src/session.c
+++ b/src/session.c
@@ -54,7 +54,7 @@
 
    state = SMTP_STATE_INIT;
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg->server_id);
    sdata.tls = 0;
 
    bzero(&counters, sizeof(counters));
@@ -370,7 +370,7 @@
                   unlink(sdata.ttmpfile);
                   unlink(sdata.tmpframe);
 
-                  init_session_data(&sdata);
+                  init_session_data(&sdata, cfg->server_id);
                }
 
                state = SMTP_STATE_MAIL_FROM;
@@ -476,7 +476,7 @@
             unlink(sdata.ttmpfile);
             unlink(sdata.tmpframe);
 
-            init_session_data(&sdata);
+            init_session_data(&sdata, cfg->server_id);
 
             state = SMTP_STATE_HELO;
 
diff --git a/src/test.c b/src/test.c
index ef03ff9..be3d7b3 100644
--- a/src/test.c
+++ b/src/test.c
@@ -60,7 +60,7 @@
    load_rules(&sdata, &(data.archiving_rules), SQL_ARCHIVING_RULE_TABLE);
    load_rules(&sdata, &(data.retention_rules), SQL_RETENTION_RULE_TABLE);
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg.server_id);
  
    sdata.sent = 0;
    sdata.delivered = 0;
diff --git a/test/debug.c b/test/debug.c
index df4e624..f1a2b2a 100644
--- a/test/debug.c
+++ b/test/debug.c
@@ -33,7 +33,7 @@
    cfg = read_config(CONFIG_FILE);
 
 
-   init_session_data(&sdata);
+   init_session_data(&sdata, cfg.server_id);
  
    sdata.sent = 0;
    sdata.tot_len = st.st_size;
diff --git a/test/ptest.c b/test/ptest.c
index 6c2a406..5b09bdd 100644
--- a/test/ptest.c
+++ b/test/ptest.c
@@ -40,7 +40,7 @@
    struct _state state;
 
 
-   init_session_data(sdata);
+   init_session_data(sdata, cfg->server_id);
 
       if(stat(filename, &st) != 0){
          printf("cannot stat() %s\n", filename);