Protect smtp server for add a blacklist ip

Good morning .
I have 1vps with the pro version and I am quite happy with this panel.

I have a question.
I want to send emails with php to a mailing list.
To protect the server and the IP address as is best.
Use different domains? use different domains with dedicated ip when all in same vps? or better that they are different domains with different ip and that they are also different servers?
The current server is fancy and I don't want to have spam problems later.
The php script sends every 5 seconds an email.


Thanks for the help

If you are doing mailing lists, I wouldn't use your vps unless you know what you are doing.  Use a service like mailchimp.  Any slight misconfiguration will guarantee your mx will be blacklisted.

The php script sends every 5 seconds an email.

This is not good. Guaranteed to get on a blacklist as it looks very like spamming.

Solution is you need to use ip rotation for postfix.

Solution is you need to use ip rotation for postfix.

Good again

And it is not better, for example, to send every 5 seconds an email but from different servers? For example:
I have 4 vps servers and use 5 seconds vps 1 for another 5 seconds vps2 for another 5 seconds vps 3 for another 5 seconds vps 4.
worth ? would you protect the vps in this way?

Solution is you need to use ip rotation for postfix.

Good again

And it is not better, for example, to send every 5 seconds an email but from different servers? For example:
I have 4 vps servers and use 5 seconds vps 1 for another 5 seconds vps2 for another 5 seconds vps 3 for another 5 seconds vps 4.
worth ? would you protect the vps in this way?

This is definitely spamming: to assist you is likely unlawful in some countries and at the least your hosting providers should shut down your server/network.