diff --git a/doc/nullmailer-send.8 b/doc/nullmailer-send.8
index 34e5f96..39bb932 100644
--- a/doc/nullmailer-send.8
+++ b/doc/nullmailer-send.8
@@ -134,6 +134,15 @@ Set the SMTP authentication password.
 .BI source= HOSTNAME
 Set the source address for connections to the remote host.
 .TP
+.BI unix-socket=\fISOCKETNAME
+Set the unix socket to connect to. When this option is set, neither
+.B port
+nor
+.B source
+can be used, and
+.B hostname
+is ignored.
+.TP
 .B auth-login
 Force SMTP "AUTH LOGIN" mode instead of auto-detecting.
 .TP
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 88e5b35..03c9c63 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -13,7 +13,7 @@ libmisc_a_SOURCES = \
 	canonicalize.h canonicalize.cc \
 	configio.h config_path.cc \
 	config_read.cc config_readlist.cc config_readint.cc config_syserr.cc \
-	connect.h tcpconnect.cc \
+	connect.h socketconnect.cc \
 	defines.h \
 	errcodes.h errcodes.cc \
 	hostname.h hostname.cc \
diff --git a/lib/connect.h b/lib/connect.h
index d3354b0..77ffdf1 100644
--- a/lib/connect.h
+++ b/lib/connect.h
@@ -2,5 +2,6 @@
 #define NULLMAILER_CONNECT__H__
 
 extern int tcpconnect(const char* hostname, int port, const char* source);
+extern int unixconnect(const char* unix_socket);
 
 #endif // NULLMAILER_CONNECT__H__
diff --git a/lib/tcpconnect.cc b/lib/socketconnect.cc
similarity index 91%
rename from lib/tcpconnect.cc
rename to lib/socketconnect.cc
index 04d2338..c34a1f4 100644
--- a/lib/tcpconnect.cc
+++ b/lib/socketconnect.cc
@@ -24,6 +24,7 @@
 #include <netdb.h>
 #include <string.h>
 #include <sys/types.h>
+#include <sys/un.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <unistd.h>
@@ -173,3 +174,19 @@ int tcpconnect(const char* hostname, int port, const char* source)
 }
 
 #endif
+
+int unixconnect(const char* unix_socket)
+{
+  struct sockaddr_un sa;
+  memset(&sa, 0, sizeof(sa));
+  sa.sun_family = AF_UNIX;
+  strncpy(sa.sun_path, unix_socket, sizeof(sa.sun_path) - 1);
+  int s = socket(PF_UNIX, SOCK_STREAM, 0);
+  if(s == -1)
+    return -ERR_SOCKET;
+  if(connect(s, (sockaddr*)&sa, sizeof(sa)) != 0) {
+    close(s);
+    return err_return(errno, ERR_CONN_FAILED);
+  }
+  return s;
+}
diff --git a/protocols/protocol.cc b/protocols/protocol.cc
index 6c43d55..5368437 100644
--- a/protocols/protocol.cc
+++ b/protocols/protocol.cc
@@ -35,6 +35,7 @@ int port = 0;
 int auth_method = AUTH_DETECT;
 int use_tls = 0;
 int use_starttls = 0;
+const char* unix_socket = 0;
 const char* remote = 0;
 const char* source = 0;
 const char* cli_help_suffix = "";
@@ -42,6 +43,8 @@ const char* cli_args_usage = "< options 3< mail-file";
 const int cli_args_min = 0;
 const int cli_args_max = 0;
 cli_option cli_options[] = {
+  { 0, "unix-socket", cli_option::string, 0, &unix_socket,
+    "Set the path to the unix socket for the remote", 0 },
   { 0, "host", cli_option::string, 0, &remote,
     "Set the hostname for the remote", 0 },
   { 'p', "port", cli_option::integer, 0, &port,
@@ -134,17 +137,23 @@ static void parse_options(void)
 int cli_main(int, char*[])
 {
   parse_options();
-  if (remote == 0)
-    protocol_fail(ERR_USAGE, "Remote host not set");
-  if (port == 0)
-    port = use_tls ? default_tls_port : default_port;
-  if (port < 0)
-    protocol_fail(ERR_USAGE, "Invalid value for port");
-  if (use_tls || use_starttls)
-    tls_init(remote);
+  if (unix_socket == 0) {
+    if (remote == 0)
+      protocol_fail(ERR_USAGE, "Remote host not set");
+    if (port == 0)
+      port = use_tls ? default_tls_port : default_port;
+    if (port < 0)
+      protocol_fail(ERR_USAGE, "Invalid value for port");
+    if (use_tls || use_starttls)
+      tls_init(remote);
+  }
+  else if (port != 0 || source != 0)
+    protocol_fail(ERR_USAGE, "Both INET and UNIX socket specified");
   fdibuf in(3, true);
   protocol_prep(in);
-  int fd = tcpconnect(remote, port, source);
+  int fd = unix_socket == 0
+    ? tcpconnect(remote, port, source)
+    : unixconnect(unix_socket);
   if(fd < 0)
     protocol_fail(-fd, "Connect failed");
   if (use_tls)