VS 2005 - Create A "post Office" Program That Will Send Html Emails Thru The System.net.mail Framework

I am a one man dev shop and need some outside opinions on how to approach this project.

I need to create a "post office" program that will send html emails thru the system.net.mail framework.

For each job submitted to the postoffice the app would need to read a user created html email string from the database, read a string of email addresses to send to and send out the emails based on a set processing time.

The first step would be to parse out the email addresses to find out how many emails it needs to send out and determine how many it would need to send per minute to complete the job in 20 minutes tops. I.e. if 1000 email addresses are submitted per job it would determine that it needs to send 50 emails per minute to complete the job.

The part I am stuck on is how I should queue the emails. If the app determines it needs to send 50 a minute should I only load up the first 50 on a timer event then get the next 50 queued up for the next timer tick? Or would it be better to load up all 1000 in a loop and build in some kind of wait time after it sends the first 50?