Block 2000+ Distribution List's from External Email
My company has started receiving a lot of spam on our internal distribution lists for whatever reason. We have a couple thousand distribution lists so we can't manually go through all of them and block them from external emails. Is there a way to build a list of all the distribution lists into Excel and add whatever syntax is needed to block them from external emails then export to a bat file to run? Essentially I would like to close off all our distribution lists from external emails the quickest way possible.