As i see when i look onto cpheader();, you want to run this script from within your admin-cp.
i think the gettemplate function doesn't work correctly in the ACP, because there is no steyleset and templateset defined, so it just looks at the global set, but you have created custom templates which aren't within the globalset..
try this code:
PHP Code:
error_reporting(7);
$templatesused = "test_1_titel,test_1_nachricht";
require("./global.php");
cpheader();
$templatesetid=1;
if(isset($touserid)) {
$useri = $DB_site->query_first("select * from user where userid='$touserid'");
$DB_site->query("update user set pmpopup='1'");
if(($first == "test1")) {
eval("\$test1titel.= \"".gettemplate("test_1_titel")."\";");
eval("\$test1nachricht.= \"".gettemplate("test_1_nachricht")."\";");
$DB_site->query("INSERT INTO privatemessage (userid,touserid,fromuserid,title,message,dateline,showsignature,iconid,messageread,folderid) VALUES ($touserid,$bbuserinfo[userid],$bbuserinfo[userid],'".addslashes(htmlspecialchars($test1titel))."','".addslashes($test1nachricht)."',".time().",'1','0',0,0)");
mail($toemail,$test1titel,$test1nachricht,"From: \"$bbtitle Mailer\" <$webmasteremail>");
echo "Alles ok...";
} elseif(($first == "test2")) {
i think this can work