I’d assume that the majority of companies larger than ~10 employees or so have this explicitly in the agreements you signed (as something that’s not allowed).

I’d assume that the majority of companies larger than ~10 employees or so have this explicitly in the agreements you signed (as something that’s not allowed). When you talk about “it could contain private info of the company”, lets be frank and say that a full copy of all your emails definitely contains private company info. It might also contain data you want, but if you worked somewhere for any length of time and actually worked, your communications contain private company info. As such, exporting it for your personal storage constitutes copying the company’s information without their knowledge or permission. It’s possible they didn’t put a prohibition on that into your contractual agreements.