It depends on what you mean by "remotely". If you have a secure connection between your workstation and the LAN segment the server is on, you can safely RDP in and manage it that way. We do that where I work on a regular basis for servers that are not domain controllers.
RSAT is more for managing Active Directory and DCs, although there are some other functions in RSAT you can use for non-DC servers.
You can also use PowerShell for remote management of DCs, servers, Exchange servers and Lync servers.
However, if by "remote" you mean connecting to said servers from outside your work network, like over the Internet, you'll want some sort of VPN solution to encrypt that traffic. You don't want to open up your firewall to allow direct outside connections to any of your servers.