They do make rack mount hardware: https://www.apple.com/shop/buy-mac/mac-pro/rack https://www.apple.com/shop/buy-mac/mac-pro/rack Don't know if that qualifies

They do make rack mount hardware: https://www.apple.com/shop/buy-mac/mac-pro/rack https://www.apple.com/shop/buy-mac/mac-pro/rack Don't know if that qualifies as server :).