How to send mail through unencrypted smtp port 25 without hemorrhoids?

Question

Mail server

There is outdated software that can only send mail through port 25. How can I create an smtp server from under Windows 2019 with minimal hemorrhoids and minimal settings? Or are there mailers back in 2020 that support sending on port 25 (naturally free)?

Answer 1

Keep
https://www.hmailserver.com/
port 25 open only on the internal interface and limit reception to one address where this tool is located.
By car it is better that there are no users, well, or conscious users with an antivirus.

Answer 2

Sending is supported, delivery is worse