How to make high-quality E-mail newsletter from your server?

Question

Email Marketing

There are several VPS, I want to learn how to make high-quality mailings, not spam.
I had experience through different projects (Sendpulse, rootsend ...) I did
mailing lists with settings for all records, HTML writing, I checked texts on different testers.
mail-tester showed 10/10
How to properly send a mailout to a database of no more than 10k letters
And how to do it to large databases.
Send emails with some delay? Or 10k emails in 10 minutes?
Send from one IP, with one subject of the letter and from one mail?
Where to change randomization?
How to overclock the server to 10k emails per day without spam? where to start and how to use?