Lots of schools and companies do this; I understand why, but it makes it hard to communicate with people at such institutions.
And that's not even considering the security and privacy risks to email users from third-party email scanning and rewriting.
I could also imagine legal issues going both ways, particularly if the third party is tempted to retain data about email users.
For example, some universities that use Gmail and Google Apps for Education (for example) required that Google not scan student email, presumably due to privacy and legal requirements, or faculty email (due to faculty objections), and Google itself ultimately abandoned the practice in the face of a lawsuit.
And that's not even considering the security and privacy risks to email users from third-party email scanning and rewriting.
I could also imagine legal issues going both ways, particularly if the third party is tempted to retain data about email users.
For example, some universities that use Gmail and Google Apps for Education (for example) required that Google not scan student email, presumably due to privacy and legal requirements, or faculty email (due to faculty objections), and Google itself ultimately abandoned the practice in the face of a lawsuit.
https://marketbrief.edweek.org/marketplace-k-12/google_aband...