How to fix PHP mail() function slow with sendmail problem

The PHP mail() function with sendmail can become slow or get blocked if the /etc/hosts file is not configured correctly. What is happening is that the mail() function is being blocked and forced to timeout based on this information. Check that the /etc/hosts file is setup with the correct hostname. If you are not sure how to do this, you may want to call customer service for your web hosting company and ask them to help you with it.