Question Spamassassin Custom Rule for contact form

[Lrnt]

Hi everyone,

I am on Debian 9.13 (Plesk Obsidian 18.0.39).

I have got a contact form on my website.

In order to properly send email (with MailJet API, that require an approved domain), I use the main email address of the domain ([email protected]) in From with the name input by the form user. Then I use ReplyTo to set the actual name and email filled by the user.

For example, this is what I get:
FROM: John Doe <[email protected]>
REPLY-TO : John Doe <[email protected]>

But for some reason Spamassassin mark my message as SPAM because of a rule FREEMAIL_FORGED_REPLYTO

Do you know how to add a custom rule that may reduce score?
If I can put a new custom rule like this, I will be able to add a custom Header in my message, so the score will be lower.

I hope my request is clear...
Thanks !