Free Alternatives Business Edition

The selections will favor the minimalist client. Ideally thru a browser

Firewall: PfSense, uses any x86 hardware, req’s 2 nics. lots of plug-ins including Wireguard.

VPN: I’m going to recommend you expose nothing to the internet. Use Tailscale overlay networking. Installs on most operating systems, create an exit node to access a whole subnet. Works with ANY firewall.

Email Spam Filter; 80% of breaches via email. rSpamD SpamAssassin(Old), Sublime (free <500)

Email Server+Calendar+Contacts: Sogo access thru a browser or M$ Outlook. Easy Install via Docker Compose

File storage: NextCloud/TrueNas. Easy Install via Docker Compose

Chat: Mattermost / RocketChat. Easy Install via Docker Compose

VoIP: 3cx has a pre-configured .ISO to install an onsite controller VM. have a customer ~20users, seems decent. The SIP service this uses is not free.

Email Client: MailSpring supports Exchange. Otherwise Thunderbird is open source