Specific e-mail addresses can be excluded from part download. The management therefor is found in the dialog area Management. There is a master list (provided by CADENAS) and a specific catalog list (maintained by the customer):
Under Section 1.2.1, “Frequently asked questions” the most frequently asked questions are found. Links leads you to the respective answers.
Then please start with Section 1.2.2, “Basics regarding functionality”.