My problem is that my transactional emails come first after round about 30 minutes or later!
Dose anybody know what I do wrong? I'm using the default mail transmitter from Magento
You can do a small change in order.php (/app/code/core/Mage/Sales/Model/Order.php)
And it is important to check whether the cronjob for the emails is set up correctly:
After Magento 1.9 the order confirmation emails are not sent during checkout anymore and instead are being sent with the cron. Make sure your Cron is working (you can check the cron logs /var/log/cron).
Also make sure Magento cron is running every five minutes. You should see something like this in Crontab (in your server):
*/5 * * * * /public_html/cron.sh