diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6da49c4d..09b5dbd6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -206,6 +206,10 @@ if(NOT LCI_WITH_LCT_ONLY)
       CACHE STRING "The default rendezvous protocol to use (write, writeimm).")
   set_property(CACHE LCI_RDV_PROTOCOL_DEFAULT PROPERTY STRINGS write writeimm)
 
+  set(LCI_MAX_SINGLE_MESSAGE_SIZE_DEFAULT
+      2000000000
+      CACHE STRING "Default single low-level message max size")
+
   mark_as_advanced(
     LCI_CONFIG_USE_ALIGNED_ALLOC
     LCI_PACKET_SIZE_DEFAULT
@@ -214,7 +218,8 @@ if(NOT LCI_WITH_LCT_ONLY)
     LCI_SERVER_MAX_CQES_DEFAULT
     LCI_SERVER_NUM_PKTS_DEFAULT
     LCI_CACHE_LINE
-    LCI_RDV_PROTOCOL_DEFAULT)
+    LCI_RDV_PROTOCOL_DEFAULT
+    LCI_MAX_SINGLE_MESSAGE_SIZE_DEFAULT)
 
   # ############################################################################
   # LCI Testing related options
diff --git a/cmake_modules/AddLCI.cmake b/cmake_modules/AddLCI.cmake
index e45e1293..f933c0d9 100644
--- a/cmake_modules/AddLCI.cmake
+++ b/cmake_modules/AddLCI.cmake
@@ -20,8 +20,8 @@ function(add_lci_executable name)
 endfunction()
 
 function(add_lci_test name)
-  cmake_parse_arguments(ARG "" "" "COMMANDS;LABELS;SOURCES;DEPENDENCIES"
-                        ${ARGN})
+  cmake_parse_arguments(
+    ARG "" "" "COMMANDS;LABELS;SOURCES;DEPENDENCIES;ENVIRONMENT" ${ARGN})
 
   add_lci_executable(${name} ${ARG_SOURCES})
   target_include_directories(${name} PRIVATE ${CMAKE_SOURCE_DIR}/src/include)
@@ -47,11 +47,15 @@ function(add_lci_test name)
     string(REPLACE " " ";" TEST_COMMAND ${TEST_COMMAND})
     add_test(NAME ${test_name} COMMAND ${TEST_COMMAND})
     set_property(TEST ${test_name} PROPERTY LABELS ${ARG_LABELS})
+    if(ENVIRONMENT)
+      set_tests_properties(${test_name} PROPERTIES ENVIRONMENT ${ENVIRONMENT})
+    endif()
   endwhile()
 endfunction()
 
 function(add_lci_tests)
-  cmake_parse_arguments(ARG "" "" "COMMANDS;LABELS;TESTS;DEPENDENCIES" ${ARGN})
+  cmake_parse_arguments(
+    ARG "" "" "COMMANDS;LABELS;TESTS;DEPENDENCIES;ENVIRONMENT" ${ARGN})
   foreach(name ${ARG_TESTS})
     string(REGEX REPLACE "\\.[^.]*$" "" name_without_ext ${name})
     add_lci_test(
@@ -63,6 +67,8 @@ function(add_lci_tests)
       COMMANDS
       ${ARG_COMMANDS}
       DEPENDENCIES
-      ${ARG_DEPENDENCIES})
+      ${ARG_DEPENDENCIES}
+      ENVIRONMENT
+      ${ENVIRONMENT})
   endforeach()
 endfunction()
diff --git a/lci/api/lci.h b/lci/api/lci.h
index b927fbf6..e0584130 100644
--- a/lci/api/lci.h
+++ b/lci/api/lci.h
@@ -438,6 +438,13 @@ extern int LCI_MEDIUM_SIZE;
  */
 extern int LCI_IOVEC_SIZE;
 
+/**
+ * @ingroup LCI_COMM
+ * @brief The maximum size (in byte) of a buffer that can be used in long
+ * messages without being broken.
+ */
+extern size_t LCI_MAX_SINGLE_MESSAGE_SIZE;
+
 /**
  * @ingroup LCI_SETUP
  * @brief Initial number of entries in a default matching table.
diff --git a/lci/api/lci_config.h.in b/lci/api/lci_config.h.in
index a1884c23..ad3c6c23 100644
--- a/lci/api/lci_config.h.in
+++ b/lci/api/lci_config.h.in
@@ -40,6 +40,7 @@
 #cmakedefine01 LCI_IBV_ENABLE_TD_DEFAULT
 #cmakedefine01 LCI_ENABLE_PRG_NET_ENDPOINT_DEFAULT
 #define LCI_RDV_PROTOCOL_DEFAULT "@LCI_RDV_PROTOCOL_DEFAULT@"
+#define LCI_MAX_SINGLE_MESSAGE_SIZE_DEFAULT @LCI_MAX_SINGLE_MESSAGE_SIZE_DEFAULT@
 
 #define LCI_CQ_MAX_POLL 16
 #define LCI_SERVER_MAX_ENDPOINTS 8
diff --git a/lci/backend/ibv/server_ibv.c b/lci/backend/ibv/server_ibv.c
index bbac265f..edf33680 100644
--- a/lci/backend/ibv/server_ibv.c
+++ b/lci/backend/ibv/server_ibv.c
@@ -76,6 +76,16 @@ void LCISI_event_polling_thread_fina(LCISI_server_t* server)
 
 void LCISD_server_init(LCIS_server_t* s)
 {
+  // Check configurations
+  if (LCI_MAX_SINGLE_MESSAGE_SIZE >= 2 << 31) {
+    // ibverbs' max message is 2GiB (or 2GB?)
+    LCI_MAX_SINGLE_MESSAGE_SIZE = 2 << 31 - 1;
+    LCI_Warn(
+        "Reduce LCI_MAX_SINGLE_MESSAGE_SIZE to %lu"
+        "as required by libibverbs max message size\n",
+        LCI_MAX_SINGLE_MESSAGE_SIZE);
+  }
+
   LCISI_server_t* server = LCIU_malloc(sizeof(LCISI_server_t));
   *s = (LCIS_server_t)server;
 
diff --git a/lci/backend/ofi/server_ofi.c b/lci/backend/ofi/server_ofi.c
index ff89b093..eb7dfa89 100644
--- a/lci/backend/ofi/server_ofi.c
+++ b/lci/backend/ofi/server_ofi.c
@@ -99,6 +99,13 @@ void LCISD_server_init(LCIS_server_t* s)
              "inject_size (%lu) < sizeof(LCI_short_t) (%lu)!\n",
              server->info->tx_attr->inject_size, sizeof(LCI_short_t));
   fi_freeinfo(hints);
+  if (server->info->ep_attr->max_msg_size < LCI_MAX_SINGLE_MESSAGE_SIZE) {
+    LCI_MAX_SINGLE_MESSAGE_SIZE = server->info->ep_attr->max_msg_size;
+    LCI_Warn(
+        "Reduce LCI_MAX_SINGLE_MESSAGE_SIZE to %lu"
+        "as required by the libfabric max_msg_size attribute\n",
+        LCI_MAX_SINGLE_MESSAGE_SIZE);
+  }
   if (strcmp(server->info->fabric_attr->prov_name, "cxi") == 0) {
     LCI_Assert(LCI_USE_DREG == 0,
                "The registration cache should be turned off "
diff --git a/lci/runtime/env.c b/lci/runtime/env.c
index 4de6506a..992fa037 100644
--- a/lci/runtime/env.c
+++ b/lci/runtime/env.c
@@ -7,6 +7,7 @@ LCI_API int LCI_MAX_ENDPOINTS;
 LCI_API int LCI_MAX_TAG = (1u << 16) - 1;
 LCI_API int LCI_MEDIUM_SIZE = -1;
 LCI_API int LCI_IOVEC_SIZE = -1;
+LCI_API size_t LCI_MAX_SINGLE_MESSAGE_SIZE;
 LCI_API int LCI_DEFAULT_QUEUE_LENGTH;
 LCI_API int LCI_MAX_QUEUE_LENGTH;
 LCI_API int LCI_MAX_SYNC_LENGTH = INT_MAX;
@@ -100,6 +101,8 @@ void LCII_env_init(int num_proc, int rank)
                (LCI_PACKET_SIZE - sizeof(struct LCII_packet_context) -
                 sizeof(struct LCII_packet_rtr_t)) /
                    sizeof(struct LCII_packet_rtr_rbuffer_info_t));
+  LCI_MAX_SINGLE_MESSAGE_SIZE = LCIU_getenv_or(
+      "LCI_MAX_SINGLE_MESSAGE_SIZE", LCI_MAX_SINGLE_MESSAGE_SIZE_DEFAULT);
   LCI_OFI_CXI_TRY_NO_HACK = LCIU_getenv_or("LCI_OFI_CXI_TRY_NO_HACK", false);
   {
     // default value
diff --git a/lci/runtime/rendezvous.h b/lci/runtime/rendezvous.h
index aa9149be..ecbceb9d 100644
--- a/lci/runtime/rendezvous.h
+++ b/lci/runtime/rendezvous.h
@@ -158,6 +158,24 @@ static void LCII_env_init_rdv_protocol()
           LCI_RDV_PROTOCOL);
 }
 
+static inline int LCII_calculate_rdma_num(LCII_context_t* ctx)
+{
+  int nrdmas = 0;
+  int nbuffers = (ctx->data_type == LCI_IOVEC) ? ctx->data.iovec.count : 1;
+  for (int i = 0; i < nbuffers; ++i) {
+    LCI_lbuffer_t* lbuffer;
+    if (ctx->data_type == LCI_LONG) {
+      lbuffer = &ctx->data.lbuffer;
+    } else {
+      LCI_DBG_Assert(ctx->data_type == LCI_IOVEC, "");
+      lbuffer = &ctx->data.iovec.lbuffers[i];
+    }
+    nrdmas += (lbuffer->length + LCI_MAX_SINGLE_MESSAGE_SIZE - 1) /
+              LCI_MAX_SINGLE_MESSAGE_SIZE;
+  }
+  return nrdmas;
+}
+
 static inline void LCII_rts_fill_rbuffer_info(
     struct LCII_packet_rtr_rbuffer_info_t* p, LCI_lbuffer_t lbuffer)
 {
@@ -219,6 +237,7 @@ static inline void LCII_handle_rts(LCI_endpoint_t ep, LCII_packet_t* packet,
                       &rdv_ctx->data.lbuffer);
     rdv_ctx->data_type = LCI_LONG;
   } else {
+    // rdv_type == LCII_RDV_IOVEC
     rdv_ctx->data.iovec.count = packet->data.rts.count;
     rdv_ctx->data.iovec.piggy_back.length = packet->data.rts.piggy_back_size;
     rdv_ctx->data.iovec.piggy_back.address =
@@ -245,7 +264,10 @@ static inline void LCII_handle_rts(LCI_endpoint_t ep, LCII_packet_t* packet,
   // Prepare the RTR packet
   // reuse the rts packet as rtr packet
   packet->context.poolid = LCII_POOLID_LOCAL;
-  if (LCI_RDV_PROTOCOL == LCI_RDV_WRITEIMM && rdv_type != LCII_RDV_IOVEC) {
+  int nrdmas = LCII_calculate_rdma_num(rdv_ctx);
+  if (nrdmas == 1 && LCI_RDV_PROTOCOL == LCI_RDV_WRITEIMM &&
+      rdv_type != LCII_RDV_IOVEC) {
+    // We cannot use writeimm for more than 1 rdma messages.
     // IOVEC does not support writeimm for now
     uint64_t ctx_key;
     int result =
@@ -298,16 +320,14 @@ static inline void LCII_handle_rtr(LCI_endpoint_t ep, LCII_packet_t* packet)
   LCII_context_t* ctx = (LCII_context_t*)packet->data.rtr.send_ctx;
   // Set up the "extended context" for write protocol
   void* ctx_to_pass = ctx;
-  if (LCI_RDV_PROTOCOL == LCI_RDV_WRITE || rdv_type == LCII_RDV_IOVEC) {
+  int nrdmas = LCII_calculate_rdma_num(ctx);
+  if (nrdmas > 1 || LCI_RDV_PROTOCOL == LCI_RDV_WRITE ||
+      rdv_type == LCII_RDV_IOVEC) {
     LCII_extended_context_t* ectx =
         LCIU_malloc(sizeof(LCII_extended_context_t));
     LCII_initilize_comp_attr(ectx->comp_attr);
     LCII_comp_attr_set_extended(ectx->comp_attr, 1);
-    if (ctx->data_type == LCI_LONG) {
-      atomic_init(&ectx->signal_count, 1);
-    } else {
-      atomic_init(&ectx->signal_count, ctx->data.iovec.count);
-    }
+    atomic_init(&ectx->signal_count, nrdmas);
     ectx->context = ctx;
     ectx->ep = ep;
     ectx->recv_ctx = packet->data.rtr.recv_ctx;
@@ -334,17 +354,31 @@ static inline void LCII_handle_rtr(LCI_endpoint_t ep, LCII_packet_t* packet)
     LCII_PCOUNTER_END(rtr_mem_reg_timer);
     // issue the put/putimm
     LCII_PCOUNTER_START(rtr_put_timer);
-    if (LCI_RDV_PROTOCOL == LCI_RDV_WRITE || rdv_type == LCII_RDV_IOVEC) {
-      LCIS_post_put_bq(ep->bq_p, ep->bq_spinlock_p,
-                       ep->device->endpoint_progress->endpoint, (int)ctx->rank,
-                       lbuffer->address, lbuffer->length, lbuffer->segment->mr,
-                       packet->data.rtr.rbuffer_info_p[i].remote_addr_base,
-                       packet->data.rtr.rbuffer_info_p[i].remote_addr_offset,
-                       packet->data.rtr.rbuffer_info_p[i].rkey, ctx_to_pass);
+    if (nrdmas > 1 || LCI_RDV_PROTOCOL == LCI_RDV_WRITE ||
+        rdv_type == LCII_RDV_IOVEC) {
+      if (lbuffer->length > LCI_MAX_SINGLE_MESSAGE_SIZE) {
+        LCI_DBG_Log(LCI_LOG_TRACE, "rdv",
+                    "Splitting a large message of %lu bytes\n",
+                    lbuffer->length);
+      }
+      for (size_t offset = 0; offset < lbuffer->length;
+           offset += LCI_MAX_SINGLE_MESSAGE_SIZE) {
+        char* address = (char*)lbuffer->address + offset;
+        size_t length =
+            LCIU_MIN(lbuffer->length - offset, LCI_MAX_SINGLE_MESSAGE_SIZE);
+        LCIS_post_put_bq(
+            ep->bq_p, ep->bq_spinlock_p,
+            ep->device->endpoint_progress->endpoint, (int)ctx->rank, address,
+            length, lbuffer->segment->mr,
+            packet->data.rtr.rbuffer_info_p[i].remote_addr_base,
+            packet->data.rtr.rbuffer_info_p[i].remote_addr_offset + offset,
+            packet->data.rtr.rbuffer_info_p[i].rkey, ctx_to_pass);
+      }
     } else {
-      LCI_DBG_Assert(
-          LCI_RDV_PROTOCOL == LCI_RDV_WRITEIMM && rdv_type != LCII_RDV_IOVEC,
-          "Unexpected rdv protocol!\n");
+      LCI_DBG_Assert(lbuffer->length <= LCI_MAX_SINGLE_MESSAGE_SIZE &&
+                         LCI_RDV_PROTOCOL == LCI_RDV_WRITEIMM &&
+                         rdv_type != LCII_RDV_IOVEC,
+                     "Unexpected rdv protocol!\n");
       LCIS_post_putImm_bq(ep->bq_p, ep->bq_spinlock_p,
                           ep->device->endpoint_progress->endpoint,
                           (int)ctx->rank, lbuffer->address, lbuffer->length,
diff --git a/tests/lcit/CMakeLists.txt b/tests/lcit/CMakeLists.txt
index 52899adf..369498a3 100644
--- a/tests/lcit/CMakeLists.txt
+++ b/tests/lcit/CMakeLists.txt
@@ -43,3 +43,13 @@ add_lci_tests(
   "${SRUN_EXE} -n 3 ${SRUN_EXTRA_ARG} [TARGET] --op 1m --nthreads 3 --send-window 1 --recv-window 100 --nsteps 10"
   "${SRUN_EXE} -n 3 ${SRUN_EXTRA_ARG} [TARGET] --op 1l --nthreads 3 --send-window 1 --recv-window 100 --nsteps 10"
 )
+
+add_lci_tests(
+  TESTS
+  lcit_pt2pt.cpp
+  LABELS
+  lcit.bigmsg
+  COMMANDS
+  "${SRUN_EXE} -n 2 ${SRUN_EXTRA_ARG} env LCI_MAX_SINGLE_MESSAGE_SIZE=1002 [TARGET] --op 2l --min-msg-size=1001 --max-msg-size=4004 --nsteps 1"
+  "${SRUN_EXE} -n 2 ${SRUN_EXTRA_ARG} env LCI_MAX_SINGLE_MESSAGE_SIZE=1002 [TARGET] --op 1l --min-msg-size=1001 --max-msg-size=4004 --nsteps 1"
+)