--- a/mailnews/local/src/nsMsgBrkMBoxStore.cpp
+++ b/mailnews/local/src/nsMsgBrkMBoxStore.cpp
@@ -583,16 +583,19 @@ nsMsgBrkMBoxStore::GetNewMsgOutputStream
   nsCOMPtr<nsIOutputStream> mboxStream;
   nsresult rv = InternalGetNewMsgOutputStream(aFolder, aNewMsgHdr,
                                               getter_AddRefs(mboxStream));
   NS_ENSURE_SUCCESS(rv, rv);
 
   RefPtr<nsQuarantinedOutputStream> qStream =
       new nsQuarantinedOutputStream(mboxStream);
   qStream.forget(aResult);
+
+  *aResult = mboxStream; // missing ???
+  
   return NS_OK;
 }
 
 nsresult nsMsgBrkMBoxStore::InternalGetNewMsgOutputStream(
     nsIMsgFolder* aFolder, nsIMsgDBHdr** aNewMsgHdr, 
     nsIOutputStream** aResult) {
   NS_ENSURE_ARG_POINTER(aFolder);
   NS_ENSURE_ARG_POINTER(aNewMsgHdr);
@@ -601,44 +604,68 @@ nsresult nsMsgBrkMBoxStore::InternalGetN
 #ifdef _DEBUG
   NS_ASSERTION(m_streamOutstandingFolder != aFolder, "didn't finish prev msg");
   m_streamOutstandingFolder = aFolder;
 #endif
 
   nsresult rv;
   nsCOMPtr<nsIFile> mboxFile;
   rv = aFolder->GetFilePath(getter_AddRefs(mboxFile));
+#ifdef DEBUG
+  fprintf(stderr,"{debug} GetFilePath failed in InternalGetNewMsgOutputStream. rv=0x%" 
+          PRIx32 "\n",
+          static_cast<uint32_t>(rv));
+#endif
   NS_ENSURE_SUCCESS(rv, rv);
   nsCOMPtr<nsIMsgDatabase> db;
   aFolder->GetMsgDatabase(getter_AddRefs(db));
   if (!db && !*aNewMsgHdr) NS_WARNING("no db, and no message header");
   bool exists = false;
   mboxFile->Exists(&exists);
   if (!exists) {
     rv = mboxFile->Create(nsIFile::NORMAL_FILE_TYPE, 0600);
+#ifdef DEBUG
+  fprintf(stderr,"{debug} mboxFile->Createfailed in InternalGetNewMsgOutputStream. rv=0x%" 
+          PRIx32 "\n",
+          static_cast<uint32_t>(rv));
+#endif
     NS_ENSURE_SUCCESS(rv, rv);
+  } else {
+#ifdef DEBUG
+    fprintf(stderr,"{debug} mboxFile existed and so did not create.\n");
+#endif
   }
 
   nsCString URI;
   aFolder->GetURI(URI);
   nsCOMPtr<nsISeekableStream> seekable;
 
-  // Note here, m_outputStreams is a hash table (maybe an array) or something
+  // Note here, m_outputStreams (note the plural) is a hash table (maybe an array) or something
   // like that in this part of code.
 
   if (m_outputStreams.Get(URI, aResult)) {
     seekable = do_QueryInterface(*aResult, &rv);
+#ifdef DEBUG
+  fprintf(stderr,"{debug} do_QueryIntgerface(*aResult, &rv) failed in InternalGetNewMsgOutputStream. rv=0x%" 
+          PRIx32 "\n",
+          static_cast<uint32_t>(rv));
+#endif
     NS_ENSURE_SUCCESS(rv, rv);
     rv = seekable->Seek(nsISeekableStream::NS_SEEK_END, 0);
     if (NS_FAILED(rv)) {
+#ifdef DEBUG
+  fprintf(stderr,"{debug} seekable->Seek() to end InternalGetNewMsgOutputStream rv=0x%" 
+          PRIx32 ", and m_outputSterams.Remoe(URI=%s)\n",
+          static_cast<uint32_t>(rv), URI.get());
+#endif
       m_outputStreams.Remove(URI);
       NS_RELEASE(*aResult);
     }
   }
-  if (!*aResult) {
+  if (!*aResult) {  // Is there case we pass a nullptg here?
     PSTREAM2(mboxFile,
              "mboxFile being passed to MsgNewBufferedFileOutputStream(): I "
              "suspect this is nil under certain circumstances.");
     rv = MsgNewBufferedFileOutputStream(aResult, mboxFile, PR_WRONLY, 00600);
 #ifdef DEBUG
     // print pathname for easy analysis of the log on tryserver.
     nsAutoCString mboxFilePath;
     // GetNativePath is not available under Windows.
@@ -668,25 +695,62 @@ nsresult nsMsgBrkMBoxStore::InternalGetN
               "rv=0x%" PRIx32 "\n",
               static_cast<uint32_t>(rv));
     }
 #endif
     NS_ASSERTION(NS_SUCCEEDED(rv), "failed opening offline store for output");
     if (NS_FAILED(rv))
       printf("failed opening offline store for %s\n", URI.get());
     NS_ENSURE_SUCCESS(rv, rv);
+    PSTREAM2(*aResult,
+             "*aResult being returned after MsgNewBufferedFileOutputStream. Is it seekable?\n");
     seekable = do_QueryInterface(*aResult, &rv);
+#ifdef DEBUG
+    if(NS_FAILED(rv)) {
+      fprintf(stderr,"{debug} do_QueryIntgerface(*aResult, &rv) failed in InternalGetNewMsgOutputStream. rv=0x%" 
+              PRIx32 " at line=%d\n",
+              static_cast<uint32_t>(rv), __LINE__);
+    }
+#endif
     NS_ENSURE_SUCCESS(rv, rv);
+
     rv = seekable->Seek(nsISeekableStream::NS_SEEK_END, 0);
+#ifdef DEBUG
+    if(NS_FAILED(rv)) {
+      fprintf(stderr,"{debug} seekable->Seek to the end  failed in InternalGetNewMsgOutputStream. rv=0x%" 
+              PRIx32 " at line=%d\n",
+              static_cast<uint32_t>(rv), __LINE__);
+    }
+#endif
     NS_ENSURE_SUCCESS(rv, rv);
+    // We have registered URI and *aResult pair in m_outputStreams.
     m_outputStreams.InsertOrUpdate(URI, *aResult);
+#ifdef DEBUG
+    fprintf(stderr,"{debu}: we have registered (%p, URI=%s) in m_outputStreams\n",
+            (void *) *aResult, URI.get());
+#endif
+
   }
+#ifdef DEBUG
+  else {
+    fprintf(stderr,
+            "{debug} *aResult was NOT null and else [do nothing] was taken in InternalGetNewMsgOutputStream.\n");
+  }
+#endif
   int64_t filePos;
-  seekable->Tell(&filePos);
-
+  // This tell can fail with remote file system during transient network errors, etc. :-(
+  // This error |rv| will be returned.
+  rv = seekable->Tell(&filePos);
+#ifdef DEBUG
+  if (NS_FAILED(rv)) {
+    fprintf(stderr, 
+            "(debug) seekable->Tell failed. rv=0x%" PRIx32 "\n",
+            static_cast<uint32_t>(rv));
+  }
+#endif
   if (db && !*aNewMsgHdr) {
     db->CreateNewHdr(nsMsgKey_None, aNewMsgHdr);
   }
 
   if (*aNewMsgHdr) {
     char storeToken[100];
     PR_snprintf(storeToken, sizeof(storeToken), "%lld", filePos);
     (*aNewMsgHdr)->SetMessageOffset(filePos);