Delete Values From Column A Specified In Column B

I'm about to start doing it manually, just wondering if there is a way to use functions in excel to do this automatically:

Here's my situation:

I have one column A, and it has 25 000 email addresses, 1 per each row, so 25 000 rows.

Then i have in another column ''B'' with 3000 email addresses.
I need to delete these 3000 email addresses from the master 25 000 list.
Is there a way to do it automaticaly?

I imagine if there was a way to set a script to delete values in Column A found in Column ''B''.

Least, I was going to try to copy the delete list and paste to master list, so I would end up duplicates of the emails that are to be deleted and they would appear highlighter with conditional highlighting.