diff --git a/src/defs.h b/src/defs.h
index ba5995e0..50b22e37 100644
--- a/src/defs.h
+++ b/src/defs.h
@@ -402,6 +402,7 @@ struct smtp_session {
    char rcptto[MAX_RCPT_TO][SMALLBUFSIZE];
    char buf[MAXBUFSIZE];
    char remote_host[INET6_ADDRSTRLEN+1];
+   char nullbyte;
    time_t lasttime;
    int protocol_state;
    int slot;
diff --git a/src/import_pilerexport.c b/src/import_pilerexport.c
index 8514a593..eb40692e 100644
--- a/src/import_pilerexport.c
+++ b/src/import_pilerexport.c
@@ -58,7 +58,7 @@ void process_buffer(char *buf, int buflen, uint64 *count, struct session_data *s
 
 
 void import_from_pilerexport(struct session_data *sdata, struct data *data, struct config *cfg){
-   int n, rc, savedlen=0, puflen;
+   int n, rc, nullbyte, savedlen=0, puflen;
    uint64 count=0;
    char *p, copybuf[2*BIGBUFSIZE+1], buf[BIGBUFSIZE], savedbuf[BIGBUFSIZE], puf[BIGBUFSIZE];
 
@@ -70,12 +70,16 @@ void import_from_pilerexport(struct session_data *sdata, struct data *data, stru
       memset(buf, 0, sizeof(buf));
       n = fread(buf, 1, sizeof(buf)-1, stdin);
 
+      int remaininglen = n;
+
       if(savedlen > 0){
          memset(copybuf, 0, sizeof(copybuf));
 
          memcpy(copybuf, savedbuf, savedlen);
          memcpy(&copybuf[savedlen], buf, n);
 
+         remaininglen += savedlen;
+
          savedlen = 0;
          memset(savedbuf, 0, sizeof(savedbuf));
 
@@ -86,8 +90,9 @@ void import_from_pilerexport(struct session_data *sdata, struct data *data, stru
       }
 
       do {
-         puflen = read_one_line(p, '\n', puf, sizeof(puf), &rc);
+         puflen = read_one_line(p, remaininglen, '\n', puf, sizeof(puf), &rc, &nullbyte);
          p += puflen;
+         remaininglen -= puflen;
 
          if(puflen > 0){
             if(rc == OK){
diff --git a/src/misc.c b/src/misc.c
index 703b21d0..5ac2dc54 100644
--- a/src/misc.c
+++ b/src/misc.c
@@ -652,34 +652,42 @@ void move_email(struct smtp_session *session){
 
    snprintf(buf, sizeof(buf)-1, "%d/%s", session->ttmpfile[0] % session->cfg->number_of_worker_processes, session->ttmpfile);
 
+   if(session->nullbyte){
+      snprintf(buf, sizeof(buf)-1, "%s/%s", ERROR_DIR, session->ttmpfile);
+      syslog(LOG_PRIORITY, "ERROR: %s contains an invalid NUL-byte, moving it to %s", session->ttmpfile, ERROR_DIR);
+   }
+
    if(rename(session->ttmpfile, buf)){
       syslog(LOG_PRIORITY, "ERROR: couldn't rename %s to %s (reason: %s)", session->ttmpfile, buf, strerror(errno));
    }
 }
 
 
-int read_one_line(char *s, int c, char *buf, int buflen, int *rc){
+int read_one_line(char *s, int slen, int c, char *buf, int buflen, int *rc, int *nullbyte){
    int i=0;
 
    *rc = ERR;
+   *nullbyte = 0;
 
    memset(buf, 0, buflen);
 
-   if(s == NULL){
-      return i;
-   }
-
-   for(; *s; s++){
+   for(int j=0; j<slen; j++){
       if(i<buflen-2){
-         buf[i] = *s;
+         if(*(s+j) == 0){
+            *nullbyte = 1;
+         }
+
+         buf[i] = *(s+j);
          i++;
 
-         if(*s == c){
+         if(*(s+j) == c){
             *rc = OK;
             break;
          }
       }
-      else break;
+      else {
+         break;
+      }
    }
 
    return i;
diff --git a/src/misc.h b/src/misc.h
index ed13c206..09abc333 100644
--- a/src/misc.h
+++ b/src/misc.h
@@ -46,7 +46,7 @@ int create_and_bind(char *listen_addr, int listen_port);
 int can_i_write_directory(char *dir);
 
 void move_email(struct smtp_session *session);
-int read_one_line(char *s, int c, char *buf, int buflen, int *rc);
+int read_one_line(char *s, int slen, int c, char *buf, int buflen, int *rc, int *nullbyte);
 
 int init_ssl_to_server(struct data *data);
 
diff --git a/src/pop3.c b/src/pop3.c
index 84e11e5b..94137fd3 100644
--- a/src/pop3.c
+++ b/src/pop3.c
@@ -100,11 +100,15 @@ int pop3_download_email(struct data *data, int i){
    int n = 0;
 
    while((n = recvtimeoutssl(data->net, buf, sizeof(buf))) > 0){
+      int remaininglen = n;
+
       if(savedlen){
          memset(copybuf, 0, sizeof(copybuf));
          memcpy(copybuf, savedbuf, savedlen);
          memcpy(&copybuf[savedlen], buf, n);
 
+         remaininglen += savedlen;
+
          savedlen = 0;
          memset(savedbuf, 0, sizeof(savedbuf));
 
@@ -115,10 +119,13 @@ int pop3_download_email(struct data *data, int i){
 
       int puflen=0;
       int rc=OK;
+      int nullbyte=0;
+
       do {
          char puf[MAXBUFSIZE];
 
-         puflen = read_one_line(p, '\n', puf, sizeof(puf)-1, &rc);
+         puflen = read_one_line(p, remaininglen, '\n', puf, sizeof(puf)-1, &rc, &nullbyte);
+         remaininglen -= puflen;
          nlines++;
 
          if(nlines == 1){
diff --git a/src/session.c b/src/session.c
index a17b89f9..b8b9ce76 100644
--- a/src/session.c
+++ b/src/session.c
@@ -99,6 +99,7 @@ void init_smtp_session(struct smtp_session *session, int slot, int sd, char *cli
    session->net.ctx = NULL;
    session->net.ssl = NULL;
 
+   session->nullbyte = 0;
    session->last_data_char = 0;
 
    session->fd = -1;
@@ -160,11 +161,13 @@ void tear_down_session(struct smtp_session **sessions, int slot, int *num_connec
 
 
 void handle_data(struct smtp_session *session, char *readbuf, int readlen, struct config *cfg){
-   int puflen, rc;
+   int puflen, rc, nullbyte;
    char *p, copybuf[BIGBUFSIZE+MAXBUFSIZE], puf[MAXBUFSIZE];
 
    // if there's something in the saved buffer, then let's merge them
 
+   int remaininglen = readlen + session->buflen;
+
    if(session->buflen > 0){
       memset(copybuf, 0, sizeof(copybuf));
 
@@ -183,8 +186,13 @@ void handle_data(struct smtp_session *session, char *readbuf, int readlen, struc
 
 
    do {
-      puflen = read_one_line(p, '\n', puf, sizeof(puf)-1, &rc);
+      puflen = read_one_line(p, remaininglen, '\n', puf, sizeof(puf)-1, &rc, &nullbyte);
       p += puflen;
+      remaininglen -= puflen;
+
+      if(nullbyte){
+         session->nullbyte = 1;
+      }
 
       // complete line: rc == OK and puflen > 0
       // incomplete line with something in the buffer: rc == ERR and puflen > 0
@@ -195,7 +203,7 @@ void handle_data(struct smtp_session *session, char *readbuf, int readlen, struc
 
          // Save incomplete line to buffer
          if(rc == ERR){
-            snprintf(session->buf, sizeof(session->buf)-1, "%s", puf);
+            memcpy(session->buf, puf, puflen);
             session->buflen = puflen;
          }