What method do scammers use to make the message reach the inbox?

What method do scammers use to make the message reach the inbox? See the example here in the message headers.

header.from=
From:
X-SID-PRA:

Authentication-Results: spf=none (sender IP is 202.100.143.128)
smtp.mailfrom=hjgotrylvhbyftamqzpsrucvw.jeokey; dkim=none (message not
signed) header.d=none;dmarc=none action=none
header.from=news-groupon.ma;
From: Weight Loss Product, Weight Loss Product <info@news-groupon.ma>
X-Sender-IP: 202.100.143.128
X-SID-PRA: info@news-groupon.ma