Why does mail mark emails from the site as spam?

Question

MODX

For some reason, mail marks emails from the site as spam, here they sent a solution to this problem
. Please, make the From header in the sent emails comply
with the RFC 5322 standard, at least in the following parts:
tools.ietf.org/html/rfc5322#section- 3 and
tools.ietf.org/html/rfc5322#page-21
Who has done this before? please help me figure it out...
as I understand it, the problem is that the &emailFrom=`--` parameter does not work, the
form is not displayed via ajax, when letters come to the mail, there is no sender, and it is written without a recipient, how to set this moment? the form is displayed in tandem with the shopkeeper

Answer 1

&emailFrom=`--`Specify, we are talking about Formit?
What is important to check that the email headers are correct for sure:
Yes, help you