Please follow the below steps to create a rule and not mark an email as spam.

Go to Automation > Rules 


Click on Create New if you have already set up rules and if this is your first rule, you will be seeing 'Create your First Rule' it will take you to the below page

There are three parts in the RULE, that is WHEN, IF and THEN.

You can set up the conditions as mentioned below for the use case of not spamming a particular email that comes from the FROM address abc@example.com.

Rules can be created with different criteria as per your use case.

WHEN condition


IF Condition


THEN condition


Once you are done with setting up the conditions you can enable the rule and save it.