send emails with delay

I assume you've some users table which maintains list of 7k email addresses. 

Now your application is connected with table and there is SEND button. At click of SEND you want to send 500 emails per hour, so I say you can use Windows scheduler and set it as job which trigger after after every hour and keep track of how many users have been sent email.

So, your stuff of sending 7k emails to users will be done by the job in 14hours. 

Let me know if you need help in Windows job setup. The advantage is you don't even need to click SEND button yourself, and it'll run by Windows scheduler every hour

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