Okey so again next problem...
Everything worked fine before i downloaded the latest xampp, now i cant even send mails anymore :/
Warning: mail() [function.mail]: SMTP server response: 554 <firstname.lastname@example.org>: Sender address rejected: 550 IP-address does not match SPF-record in C:\xampp\htdocs\yoursite\sources\sendmessage.php on line 116
What does that mean ? :/