How do you get into inbox?

Question

SMTP

Hello. I sit and write a question: angry, angry, desperate. Joke.
Why are you angry? Yes, because I have already killed 16 smtp servers in vain. How? Easily.
I want to make a good mailing via smtp server. What does good mean? Well, send out 50 thousand letters with an inbox of 85%. And for the 16th time, I failed.
What am I doing. I buy a vps server for 365 rubles, I take a domain, I delegate it. On the server I prescribe all the necessary entries, namely: mx, spf, dkim, a, dmark, ptr. Email headers are amazing.
Next, I send 500 simple random letters to my 500 soapboxes in order to warm up this server. Well, so that somewhere in the mail, statistics are displayed that 500 letters were sent from the server, 113 were opened and not a single complaint.
Then I compose my letter, make randoms, redirects and send it. After such painful actions, ALREADY 16 TIMES IN A ROW INBOX FROM 2% TO 32%!
Guys, I'm desperate, I don't know what to do. Who knows what the problem is and how to solve it, help. I have clients for mailings, I can give them to you - those who will help me.
Thank you very much for your attention!)

Answer 1

these are spam filters for sure, you are not the only one so smart to make a mailing list with VPS)))) Better use servers for mailing, more expensive but reliable.