diff --git a/davmail.sh b/davmail.sh
index 5f7ee6d6..2a5b4e4a 100644
--- a/davmail.sh
+++ b/davmail.sh
@@ -1,8 +1,8 @@
-#!/bin/bash
+#!/bin/sh
 # Ubuntu setup instructions :
 # install java :
-# sudo apt-get install sun-java6-bin
-# launch davmail :
+# sudo apt-get install default-jre
+# launch davmail
 BASE=`dirname $0`
 for i in $BASE/lib/*; do export CLASSPATH=$CLASSPATH:$i; done
-java -cp $BASE/davmail.jar:$CLASSPATH davmail.DavGateway $1
+exec java -Xmx512M -Dsun.net.inetaddr.ttl=60 -cp $BASE/davmail.jar:$CLASSPATH davmail.DavGateway $1
diff --git a/src/bin/davmail b/src/bin/davmail
index f1e0eaf5..86fd3955 100644
--- a/src/bin/davmail
+++ b/src/bin/davmail
@@ -1,4 +1,7 @@
 #!/bin/sh
+#
+# Usage: davmail [</path/to/davmail.properties>]
+#
 export LD_LIBRARY_PATH=/usr/lib/jni
 for i in /usr/share/davmail/lib/*; do export CLASSPATH=$CLASSPATH:$i; done
-java -Xmx512M -cp /usr/share/davmail/davmail.jar:/usr/share/java/swt.jar:$CLASSPATH davmail.DavGateway "$@" 
+exec java -Xmx512M -Dsun.net.inetaddr.ttl=60 -cp /usr/share/davmail/davmail.jar:/usr/share/java/swt.jar:$CLASSPATH davmail.DavGateway "$@"