Hello guys,
I know how hard it is today to create a working MTA 0.5 server in linux environments, so I've created a docker image, which is very easy to use. It is on docker hub: https://hub.docker.com/r/andrasszell/mta05-server/
I've also started a dedicated server in EU Frankfurt:
18.195.8.184:2003
I'm also planning to create a simple web-based server browser, stay tuned.