Yes, you may. Your employer may impose conditions on the use of e-mail, Internet and business telephone at work. Or prohibit certain types of use. Then, your employer may implement controls.
Your employer does need to let you know what the rules are and that verification is possible. And your employer must comply with the terms of the privacy law, the AVG.
Read more: Control of communication devices
Source: https://www.autoriteitpersoonsgegevens.nl/themas/werk-en-uitkering/controle-van-werknemers#mag-mijn-werkgever-mijn-e-mail-internet-en-telefoongebruik-controleren , accessed May 15, 2024.