99.9% of email from gmail is spam; however, I have one family member who has a gmail account. I'm tired of blocking individual gmail and would like to BlockList the domain. If I do so, then WelcomeList my family member's address, will I receive her email or will the BlockListed domain override that? Thanks!
Yes, that should work. As long as your family member doesn't send things that otherwise look a lot like spam to our filters.
I believe the BlockList and WelcomeList both change the spam score by the same amount, but in opposite directions; so if you do that setup you family member's email should get a 0 score from the lists (and just get scored on other measures).