diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2e464d69d..ee7080cd2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,7 @@
 project(kmail)
 
+check_include_files(fcntl.h HAVE_FCNTL_H)
+check_include_files(byteswap.h HAVE_BYTESWAP_H)
 configure_file(config-kmail.h.cmake ${CMAKE_CURRENT_BINARY_DIR}/config-kmail.h )
 
 
diff --git a/configuredialog.cpp b/configuredialog.cpp
index 33669476e..68d9bb6b7 100644
--- a/configuredialog.cpp
+++ b/configuredialog.cpp
@@ -91,6 +91,7 @@ using KMime::DateFormatter;
 #include <kconfig.h>
 #include <kcmultidialog.h>
 #include <knotifyconfigwidget.h>
+#include <kresolver.h>
 
 // Qt headers:
 #include <QBoxLayout>
@@ -1035,18 +1036,8 @@ void AccountsPage::SendingTab::doLoadOther() {
   mConfirmSendCheck->setChecked(
       composer.readEntry( "confirm-before-send", false ) );
   QString str = general.readEntry( "Default domain" );
-  if( str.isEmpty() )
-  {
-    //### FIXME: Use the global convenience function instead of the homebrewed
-    //           solution once we can rely on HEAD kdelibs.
-    //str = KGlobal::hostname(); ???????
-    char buffer[256];
-    if ( !gethostname( buffer, 255 ) )
-      // buffer need not be NUL-terminated if it has full length
-      buffer[255] = 0;
-    else
-      buffer[0] = 0;
-    str = QString::fromLatin1( *buffer ? buffer : "localhost" );
+  if( str.isEmpty() ) {
+    str = KNetwork::KResolver::localHostName();
   }
   mDefaultDomainEdit->setText( str );
 }
diff --git a/keyresolver.cpp b/keyresolver.cpp
index 31f332187..0b7b561e8 100644
--- a/keyresolver.cpp
+++ b/keyresolver.cpp
@@ -389,9 +389,7 @@ static QString canonicalAddress( const QString & _address ) {
   const QString address = EmailAddressTools::extractEmailAddress( _address );
   if ( !address.contains('@') ) {
     // local address
-    //char hostname[1024];
-    //gethostname(hostname,1024);
-    //return address + '@' + hostname;
+    //return address + '@' + KNetwork::KResolver::localHostName();
     return address + "@localdomain";
   }
   else
diff --git a/kmmessage.cpp b/kmmessage.cpp
index 80e20f6ec..6295292d6 100644
--- a/kmmessage.cpp
+++ b/kmmessage.cpp
@@ -40,6 +40,7 @@ using KMail::HeaderStrategy;
 #include <khtml_part.h>
 #include <kuser.h>
 #include <kidna.h>
+#include <kresolver.h>
 
 #include <QList>
 #include <QCursor>
@@ -3740,15 +3741,9 @@ QString KMMessage::guessEmailAddressFromLoginName( const QString& loginName )
   if ( loginName.isEmpty() )
     return QString();
 
-  char hostnameC[256];
-  // null terminate this C string
-  hostnameC[255] = '\0';
-  // set the string to 0 length if gethostname fails
-  if ( gethostname( hostnameC, 255 ) )
-    hostnameC[0] = '\0';
   QString address = loginName;
   address += '@';
-  address += QString::fromLocal8Bit( hostnameC );
+  address += KNetwork::KResolver::localHostName();
 
   // try to determine the real name
   const KUser user( loginName );
diff --git a/kmstartup.cpp b/kmstartup.cpp
index c025544c7..a623c1754 100644
--- a/kmstartup.cpp
+++ b/kmstartup.cpp
@@ -32,6 +32,7 @@
 #include <kglobal.h>
 #include <kaboutdata.h>
 #include <kiconloader.h>
+#include <kresolver.h>
 
 #include <errno.h>
 #include <sys/types.h>
@@ -77,18 +78,6 @@ void kmsetSignalHandler(void (*handler)(int))
 }
 //-----------------------------------------------------------------------------
 
-namespace {
-  QString getMyHostName() {
-    char hostNameC[256];
-    // null terminate this C string
-    hostNameC[255] = 0;
-    // set the string to 0 length if gethostname fails
-    if(gethostname(hostNameC, 255))
-      hostNameC[0] = 0;
-    return QString::fromLocal8Bit(hostNameC);
-  }
-} // anon namespace
-
 namespace KMail {
 
 void checkConfigUpdates() {
@@ -149,7 +138,7 @@ void lockOrDie() {
   const QString oldHostName = config.readEntry("hostname");
   const QString oldAppName = config.readEntry( "appName", appName );
   const QString oldProgramName = config.readEntry( "programName", programName );
-  const QString hostName = getMyHostName();
+  const QString hostName = KNetwork::KResolver::localHostName();
   bool first_instance = false;
   if ( oldPid == -1 )
       first_instance = true;