diff --git a/interface/lib/classes/validate_dkim.inc.php b/interface/lib/classes/validate_dkim.inc.php
index 71b8e85205bda4393a9942b1d10b585ddec692d9..71fd8c5454a847b1877cd9d74e81502538803851 100644
--- a/interface/lib/classes/validate_dkim.inc.php
+++ b/interface/lib/classes/validate_dkim.inc.php
@@ -73,7 +73,7 @@ class validate_dkim {
 	 * @return boolean - true if $POST contains a real key-file
 	 */
 	function validate_post($key, $value, $dkim_strength) {
-		$value=str_replace("\n", "", $value);
+		$value=str_replace(array("\n", "-----BEGIN RSA PRIVATE KEY-----", "-----END RSA PRIVATE KEY-----", " "), "", $value);
 		switch ($key) {
 		case 'public':
 			if (preg_match("/(^-----BEGIN PUBLIC KEY-----)[a-zA-Z0-9\r\n\/\+=]{1,221}(-----END PUBLIC KEY-----(\n|\r)?$)/", $value) === 1) { return true; } else { return false; }
@@ -82,7 +82,7 @@ class validate_dkim {
 			if ( $dkim_strength == 1024 ) $range = "{812,816}";
 			if ( $dkim_strength == 2048 ) $range = "{1588,1592}";
 			if ( $dkim_strength == 4096 ) $range = "{3132,3136}";
-			if (preg_match("/^-----BEGIN RSA PRIVATE KEY-----[a-zA-Z0-9\/\+=]".$range."-----END RSA PRIVATE KEY-----$/", $value) === 1) return true; else return false;
+			if ( preg_match("/^[a-zA-Z0-9\/\+=]".$range."$/", $value ) === 1) return true; else return false;
 			break;
 		}
 	}