WE NEED SOME ADVICES: What is the best way for sending a huge amount of emails?

Hi everyone! We will appreciate some advices. We are new to PHP, thus, please, be patient! :) We want to make a script which needs to send a huge amount of emails (The emails are stored in a MySQL DB). We would like to take control of sending errors and put these in a log file. The script needs to send TXT, HTML,images, and even small files. Both the email content and the settings will be prepared through a HTML interface. We will need a sort of queue where we would be able to put some "Bad emails" on it in order to resend them as much times as it was set in the settings (HTML). So, How is the best way for making that PHP script, considering security, reliability (Handling email errors) and speed? Thanks in advance