Fehlermeldungen beim Absenden von Beiträgen oder PN's

Information:
error message: 
error code: 0
file: D:\xampp\htdocs\wcf\lib\system\WCF.class.php (281)
php version: 5.3.0
wcf version: 1.1.5 (Tempest)
date: Mon, 04 Apr 2011 16:44:47 +0000
request: /index.php?form=PMNew
referer: http://www.a3quattro.de/index.php?form=PMNew




Stacktrace:
#0 [internal function]: WCF::handleError(2, 'fsockopen() [<a...', 'D:\xampp\htdocs...', 39, Array)
#1 D:\xampp\htdocs\wcf\lib\system\io\RemoteFile.class.php(39): fsockopen('smtp.strato.de', 25, 10060, 'Ein Verbindungs...', 30)
#2 D:\xampp\htdocs\wcf\lib\data\mail\SMTPMailSender.class.php(42): RemoteFile->__construct('smtp.strato.de', 25)
#3 D:\xampp\htdocs\wcf\lib\data\mail\SMTPMailSender.class.php(115): SMTPMailSender->connect()
#4 D:\xampp\htdocs\wcf\lib\data\mail\Mail.class.php(189): SMTPMailSender->sendMail(Object(Mail))
#5 D:\xampp\htdocs\wcf\lib\data\message\pm\PMEditor.class.php(373): Mail->send()
#6 D:\xampp\htdocs\wcf\lib\form\PMNewForm.class.php(431): PMEditor->sendNotifications(Array)
#7 D:\xampp\htdocs\wcf\lib\form\PMNewForm.class.php(260): PMNewForm->sendNotification()
#8 D:\xampp\htdocs\wcf\lib\form\PMNewForm.class.php(121): PMNewForm->save()
#9 D:\xampp\htdocs\wcf\lib\form\AbstractForm.class.php(90): PMNewForm->submit()
#10 D:\xampp\htdocs\wcf\lib\form\CaptchaForm.class.php(104): AbstractForm->readData()
#11 D:\xampp\htdocs\wcf\lib\form\MessageForm.class.php(193): CaptchaForm->readData()
#12 D:\xampp\htdocs\wcf\lib\form\PMNewForm.class.php(279): MessageForm->readData()
#13 D:\xampp\htdocs\wcf\lib\page\AbstractPage.class.php(90): PMNewForm->readData()
#14 D:\xampp\htdocs\wcf\lib\form\MessageForm.class.php(237): AbstractPage->show()
#15 D:\xampp\htdocs\wcf\lib\form\PMNewForm.class.php(423): MessageForm->show()
#16 D:\xampp\htdocs\wcf\lib\page\AbstractPage.class.php(46): PMNewForm->show()
#17 D:\xampp\htdocs\wcf\lib\util\RequestHandler.class.php(64): AbstractPage->__construct()
#18 D:\xampp\htdocs\wcf\lib\util\RequestHandler.class.php(95): RequestHandler->__construct('PMNew', Array, 'form')
#19 D:\xampp\htdocs\index.php(8): RequestHandler::handle(Array)
#20 {main}