At my previous company (a big semiconductor vendor) the legal dept made it clear that if you had a question, you did not ask them by text. You rang them, because that made it privileged. But they didn't try to escape from discovery of emails - they were retained.

Actually they wanted some retention, because for them a big thing was to have evidence of the date you invented something in case of patent litigation. Everyone was given a paper journal in which you were supposed to make notes, which I totally failed to do.