Downloading Server Plus 5.9.25 for Mac from the developer's website was possible when we last checked. We cannot confirm if there is a free download of this app available.
According to the results of the Google Safe Browsing check, the developer's site is safe. Despite this, we recommend checking the downloaded files with any free antivirus software. The program is included in Internet & Network Tools. This free Mac application is a product of C & E Enterprises, LLC.
From the developer:
Server Plus is a server package for macOS with support for PHP 7.3 and 8.0. It is a mail server for macOS with the latest build of open source mail server components. The utility is independent from the operating system supplied components. Not just an e-mail server, the tool also provides virus checking using Clamav with hourly updates to virus signatures.
You may want to check out more Mac applications, such as PS3 Media Server, Universal Media Server or VPN Server Agent, which might be similar to Server Plus.