diff --git a/admin/assignsample.php b/admin/assignsample.php
index 492ca220..3c1baf25 100644
--- a/admin/assignsample.php
+++ b/admin/assignsample.php
@@ -106,6 +106,7 @@ if (isset($_GET['questionnaire_id']) && isset($_GET['sample'])  && isset($_GET['
 	if (isset($_GET['generatecases']))
 	{
 		include_once("../functions/functions.operator.php");
+		include_once("../functions/functions.limesurvey.php");
 
 		$db->StartTrans();
 
@@ -139,10 +140,11 @@ if (isset($_GET['questionnaire_id']) && isset($_GET['sample'])  && isset($_GET['
 
 		$db->Execute($sql);
 
-		//generate one case for each sample record and set outcome to 41
-		$sql = "SELECT sample_id
-			FROM sample
-			WHERE import_id = '$sid'";
+		//generate one case for each sample record and set outcome to 41 (where an email address provided)
+		$sql = "SELECT s.sample_id, sv.val as email
+			FROM sample as s
+			LEFT JOIN (sample_var as sv, sample_import_var_restrict as sivr) ON (sv.sample_id = s.sample_id and sv.var_id = sivr.var_id and sivr.type = 8)
+			WHERE s.import_id = '$sid'";
 
 		$rs = $db->GetAll($sql);
 
@@ -151,9 +153,12 @@ if (isset($_GET['questionnaire_id']) && isset($_GET['sample'])  && isset($_GET['
     {
       $count++;
 		  set_time_limit(30);			
-      if (add_case($r['sample_id'],$questionnaire_id,"NULL",$testing,41, true) === false) {
-        $error .= "<br/>Failed to add case for record #$count";    
-      }
+	//only if a valid email
+	if (validate_email($r['email'])) {
+	      if (add_case($r['sample_id'],$questionnaire_id,"NULL",$testing,41, true) === false) {
+        	$error .= "<br/>Failed to add case for record #$count";    
+	      }
+	}
 		}
 
 		$db->CompleteTrans();
@@ -415,7 +420,7 @@ if ($questionnaire_id != false)
 		
 		<?php $self_complete = $db->GetOne("SELECT self_complete FROM questionnaire WHERE questionnaire_id = '$questionnaire_id'");
 		if ($self_complete) {?>
-		<label for="generatecases" class="control-label col-lg-4"><?php echo T_("Generate cases for all sample records and set outcome to 'Self completion email invitation sent'?");?></label>
+		<label for="generatecases" class="control-label col-lg-4"><?php echo T_("Generate cases for all sample records with a valid email address and set outcome to 'Self completion email invitation sent'?");?></label>
 		<div class="col-sm-1"><input type="checkbox" id = "generatecases" name="generatecases" class="col-sm-1" data-toggle="toggle" data-size="small" data-on="<?php echo T_("Yes");?>" data-off="<?php echo T_("No");?>" data-width="85"/></div>
 		<em class="control-label"> * <?php echo T_("Ideal if you intend to send an email invitation to sample members before attempting to call using queXS");?></em>
 		<div class='clearfix '></div></br>