diff --git a/src/Postmark/PostmarkClient.php b/src/Postmark/PostmarkClient.php
index ccc32cf6..4cf5cce6 100644
--- a/src/Postmark/PostmarkClient.php
+++ b/src/Postmark/PostmarkClient.php
@@ -52,6 +52,7 @@ function sendEmail($from, $to, $subject, $htmlBody = NULL, $textBody = NULL,
 		$body['Subject'] = $subject;
 		$body['HtmlBody'] = $htmlBody;
 		$body['TextBody'] = $textBody;
+		$body['Tag'] = $tag;
 		$body['ReplyTo'] = $replyTo;
 		$body['Headers'] = $this->fixHeaders($headers);
 		$body['TrackOpens'] = $trackOpens;
@@ -664,4 +665,4 @@ function deleteInboundRuleTrigger($id) {
 	}
 }
 
-?>
\ No newline at end of file
+?>