Is it possible to run an SMTP server like postfix on a Google Cloud instance without using an external mail provider by relay?
Objective: Need to install an SMTP server (preferably postfix) that will send messages to other common mail providers like gmail, outlook, yahoo, etc. Problem: Google Cloud blocks usage of SMTP port 25 (but not 465 or 587) and only provides details on how to use external mail providers. Another workaround is to create a gmail account, configure relay as smtp