Hi guys, i know this port 25 issue has been spoken about before, however, i need clarification. Google Cloud documentation says... Google Compute Engine does not allow outbound connections on ports 25, 465, and 587. By default, these outbound SMTP ports are blocked because of the large amount of abuse these ports are susceptible to. it then goes on to say... While sending email from blocked ports is not allowed, your instances can still receive email. In addition to the above, it now gets confusing... Although standard email ports are blocked, you can choose a non-standard port to send email through. If you don't have a G Suite account or don't want to use G Suite or a third-party mail provider, you can set up your own email server on an instance using a non-standard port. You can choose any ephemeral port that isn't blocked by Compute Engine. So my question is this... If Google Cloud Compute can recieve mail on port 25,465, and 587, and we can configure for example Postfix to send outgoing mail on say port 2525 (as recomended by google), why would i still need to use a 3rd party mail relay for outgoing mail? Cant i just send mail on port 2525 from my ispconfig google cloud compute instance postfix server?