I'm building a website with a pretty big database of people and this will send like a newsletter sometimes.
There be like 5.000 mails being sent at one time. This is meant to be sent from a script.

Is there anything I should think bout when writing this?
Should there be some code waiting for the server until it's been sent or anything like that?
Or can the script run and send things like this without a problem?

I heard from my web host, that the only thing I have to setup is an e-mail that exist on the server that the script is sending from. Then there is no limit to how many I can send at one time they said.

So, it's just the script I'm worried about, so I make that one correct.