Email Campaign to 20,000 Contacts

I am looking for a freelancer who has very extensive experience in email marketing. I have a list of 20,000 contacts - and I have one message for a campaign - and I want this message to reach 20,000 contacts on the inbox Not spam or junk - and my condition is that the message be delivered to the inbox

- knowing that it is on the list. Of the 20,000, there are special emails that I set to ensure that the message reaches the inbox