diff --git a/test/config/dovecot-lmtp/dh.pem b/test/config/dovecot-lmtp/dh.pem
new file mode 100644
index 00000000..4ebe8dd2
--- /dev/null
+++ b/test/config/dovecot-lmtp/dh.pem
@@ -0,0 +1,8 @@
+-----BEGIN DH PARAMETERS-----
+MIIBCAKCAQEAlYgX/PXMu60WVkgKXOqnT562wd2F3l1WDwyn7DLWDqb9rCI6SAB8
+8uDkImAeoRFQycL77fXBqO9KKVk5x569Qjltacbw4/taOhWPAq/+6Wf5bZsUEp5g
+wD+hLvgYn/0pdGkjiAJ+jlRBxarF9lJac4QPztqw3qJPtVdIKbmo58hoxERIthD2
+f/ZkGjaZXzOIvD8Ai0NQ+H4k5DK5dLlFI78XbrsH161t4Jcspq+v5VUdUyUMAvti
+4peK0RgHw47h90kkee+qIf5F+WWSw28tjkbILWx2ld/bN59eZj4itb3UUw/OZRpC
+Y0pOBOvl1wp5PS+pUJAMsg6PR50yPNYREwIBAg==
+-----END DH PARAMETERS-----
diff --git a/test/config/relay-hosts/dhparams.pem b/test/config/relay-hosts/dhparams.pem
new file mode 100644
index 00000000..4ebe8dd2
--- /dev/null
+++ b/test/config/relay-hosts/dhparams.pem
@@ -0,0 +1,8 @@
+-----BEGIN DH PARAMETERS-----
+MIIBCAKCAQEAlYgX/PXMu60WVkgKXOqnT562wd2F3l1WDwyn7DLWDqb9rCI6SAB8
+8uDkImAeoRFQycL77fXBqO9KKVk5x569Qjltacbw4/taOhWPAq/+6Wf5bZsUEp5g
+wD+hLvgYn/0pdGkjiAJ+jlRBxarF9lJac4QPztqw3qJPtVdIKbmo58hoxERIthD2
+f/ZkGjaZXzOIvD8Ai0NQ+H4k5DK5dLlFI78XbrsH161t4Jcspq+v5VUdUyUMAvti
+4peK0RgHw47h90kkee+qIf5F+WWSw28tjkbILWx2ld/bN59eZj4itb3UUw/OZRpC
+Y0pOBOvl1wp5PS+pUJAMsg6PR50yPNYREwIBAg==
+-----END DH PARAMETERS-----
diff --git a/test/test_helper/common.bash b/test/test_helper/common.bash
index 82fb86c5..00d1635f 100644
--- a/test/test_helper/common.bash
+++ b/test/test_helper/common.bash
@@ -5,6 +5,7 @@ NAME=tvial/docker-mailserver:testing
 
 # default timeout is 120 seconds
 TEST_TIMEOUT_IN_SECONDS=${TEST_TIMEOUT_IN_SECONDS-120}
+NUMBER_OF_LOG_LINES=${NUMBER_OF_LOG_LINES-10}
 
 function repeat_until_success_or_timeout {
     if ! [[ "$1" =~ ^[0-9]+$ ]]; then
@@ -31,16 +32,25 @@ function wait_for_smtp_port_in_container() {
 
 # @param $1 name of the postfix container
 function wait_for_finished_setup_in_container() {
-    repeat_until_success_or_timeout $TEST_TIMEOUT_IN_SECONDS sh -c "docker logs $1 | grep 'is up and running'"
+    local status=0
+    repeat_until_success_or_timeout $TEST_TIMEOUT_IN_SECONDS sh -c "docker logs $1 | grep 'is up and running'" || status=1
+    if [[ $status -eq 1 ]]; then
+        echo "Last $NUMBER_OF_LOG_LINES lines of container \`$1\`'s log"
+        docker logs $1 | tail -n $NUMBER_OF_LOG_LINES
+    fi
+    return $status
 }
 
-SETUP_FILE_MARKER="$BATS_TMPDIR/`basename \"$BATS_TEST_FILENAME\".setup_file`"
+SETUP_FILE_MARKER="$BATS_TMPDIR/`basename \"$BATS_TEST_FILENAME\"`.setup_file"
 
 # use in setup() in conjunction with a `@test "first" {}` to trigger setup_file reliably
 function run_setup_file_if_necessary() {
     if [ "$BATS_TEST_NAME" == 'test_first' ]; then
-        rm -f "$SETUP_FILE_MARKE"
+        # prevent old markers from marking success or get an error if we cannot remove due to permissions
+        rm -f "$SETUP_FILE_MARKER"
+
         setup_file
+
         touch "$SETUP_FILE_MARKER"
     else
         if [ ! -f "$SETUP_FILE_MARKER" ]; then
@@ -53,7 +63,8 @@ function run_setup_file_if_necessary() {
 # use in teardown() in conjunction with a `@test "last" {}` to trigger teardown_file reliably
 function run_teardown_file_if_necessary() {
     if [ "$BATS_TEST_NAME" == 'test_last' ]; then
-        rm -f "$SETUP_FILE_MARKE"
+        # cleanup setup file marker
+        rm -f "$SETUP_FILE_MARKER"
         teardown_file
     fi
 }