--- a/src/internfile/mh_mbox.cpp
+++ b/src/internfile/mh_mbox.cpp
@@ -29,6 +29,7 @@
 #include <cstring>
 #include <map>
 
+#include "cstr.h"
 #include "mimehandler.h"
 #include "debuglog.h"
 #include "readfile.h"
@@ -144,7 +145,7 @@
         string blk1;
         blk1.append("udi=");
         blk1.append(udi);
-        blk1.append("\n");
+        blk1.append(cstr_newline);
         blk1.resize(o_b1size, 0);
         if (fwrite(blk1.c_str(), 1, o_b1size, fp) != o_b1size) {
             LOGDEB(("MboxCache::put_offsets: fwrite errno %d\n", errno));
@@ -384,7 +385,7 @@
     }
     FILE *fp = (FILE *)m_vfp;
     int mtarg = 0;
-    if (m_ipath != "") {
+    if (!m_ipath.empty()) {
 	sscanf(m_ipath.c_str(), "%d", &mtarg);
     } else if (m_forPreview) {
 	// Can't preview an mbox. 
@@ -434,7 +435,7 @@
     off_t message_end = 0;
     bool iseof = false;
     bool hademptyline = true;
-    string& msgtxt = m_metaData["content"];
+    string& msgtxt = m_metaData[cstr_content];
     msgtxt.erase();
     line_type line;
     for (;;) {
@@ -498,8 +499,8 @@
     // m_msgnum was incremented when hitting the next From_ or eof, so the data
     // is for m_msgnum - 1
     sprintf(buf, "%d", m_msgnum - 1); 
-    m_metaData["ipath"] = buf;
-    m_metaData["mimetype"] = "message/rfc822";
+    m_metaData[cstr_ipath] = buf;
+    m_metaData[cstr_mimetype] = "message/rfc822";
     if (iseof) {
 	LOGDEB2(("MimeHandlerMbox::next: eof hit\n"));
 	m_havedoc = false;
@@ -590,7 +591,7 @@
 	    exit(1);
 	}
 	map<string, string>::const_iterator it = 
-	    mh.get_meta_data().find("content");
+	    mh.get_meta_data().find(cstr_content);
 	int size;
 	if (it == mh.get_meta_data().end()) {
 	    size = -1;
@@ -610,7 +611,7 @@
 	}
 	docnt++;
 	map<string, string>::const_iterator it = 
-	    mh.get_meta_data().find("content");
+	    mh.get_meta_data().find(cstr_content);
 	int size;
 	if (it == mh.get_meta_data().end()) {
 	    size = -1;