diff --git a/etc/docker/defaults/greeting.html b/etc/docker/defaults/greeting.html
index 88b22fd..6277e7c 100644
--- a/etc/docker/defaults/greeting.html
+++ b/etc/docker/defaults/greeting.html
@@ -13,5 +13,7 @@ of 300 messages per mailbox - the oldest messages will be deleted to stay under
 that limit.</p>
 
 <p>Messages addressed to any recipient in the <code>@bitbucket.local</code>
-domain will be accepted but not written to disk.  Use this domain for load or
-soak testing your application.</p>
+domain will be accepted, but immediately <b>discarded</b> without being written
+to disk. Use this domain for load or soak testing your application.  Inbucket
+will retain mail for any other domain by default, i.e.
+<code>@inbucket.local</code>.</p>
diff --git a/etc/docker/docker-run.sh b/etc/docker/docker-run.sh
index 8c92e8b..cd52469 100755
--- a/etc/docker/docker-run.sh
+++ b/etc/docker/docker-run.sh
@@ -25,6 +25,9 @@ main() {
         usage
         exit
         ;;
+      -b)
+        build
+        ;;
       -r)
         reset
         ;;
@@ -38,6 +41,8 @@ main() {
     esac
   done
 
+  set -x
+
   docker run $run_opts \
     -p $PORT_HTTP:9000 \
     -p $PORT_SMTP:2500 \
@@ -49,14 +54,21 @@ main() {
 
 usage() {
   echo "$0 [options]" 2>&1
+  echo "  -b    build - build image before starting" 2>&1
   echo "  -d    detach - detach and print container ID" 2>&1
   echo "  -r    reset - purge config and data before startup" 2>&1
   echo "  -h    help - print this message" 2>&1
 }
 
+build() {
+  echo "Building $IMAGE"
+  docker build . -t "$IMAGE"
+  echo
+}
+
 reset() {
-  /bin/rm -rf "$VOL_CONFIG"
-  /bin/rm -rf "$VOL_DATA"
+  rm -rf "$VOL_CONFIG"
+  rm -rf "$VOL_DATA"
 }
 
 main $*