[dusted]

No, I mean sending the mail, outgoing, running a mailserver and receiving mail is generally not a problem.

Let's say your email server is running on blueflow.person How do I send you an email on port 587 + authenticaion ? I'd need an account on your server to do that.. That's just silly! We can't expect everyone to have accounts on every mailserver, just to send email to eachother, that'd be like the postman having to have keys to every postbox to deliver letters!

Port 25 is where your email server expects to receive emails from other mailservers (like mine).

[blueflow]

You misunderstood it horribly.

https://en.wikipedia.org/wiki/Simple_Mail_Transfer_Protocol#...