highsky

Quick Assist is build in from MS for remote Support on W10.

Smoothwall has free Open SSL VPN. There's a guide on the forum plus the have their how to in their site. Rdcman for onsite or via VPN. Wakeonlanx , for wake on LAN. But needs Mac addresses also.

The MS O365 Lab Kit above is a full working lab with just a click, Sccm ,Mdt, Vpn, clients, etc valid for 3 months. They keep releasing updated versions. Gamified version of VMware with access to their hands on labs: https://www.cloudcredibility.com/ For them free servers, Azure credits, Pluralsight offer and more, former Dreamspark - Imagine: https://azureforeducation.microsoft.com/devtools

Is this one from Sans any good: https://www.sans.org/security-resources/policies/network-security/pdf/remote-access-policy

Another way is whitelist or blacklist user or groups from sending email to mail lists. Depending on where your exchange is hosted , this can be done via PS, gui or the attributes field.

Yes, and yes. The assistant needs to login with an o365 account or an Microsoft free one.

I had to figure bit about them recently. Your firewall doesn't give you any VPN options? Our one gives a few, we went for the Open SSL one. After configuring the options you get to export the client file, install it and import the settings.