On Sun, Dec 29, 2024 at 17:25:40 +0000, mick.crane wrote:
hello
I'm not really understanding the internet.
Can I do my own SMTP server and send mail off to the right place
without
having the device open to random internet connections?
Are you envisioning mail as "outgoing only", with nobody ever able to
respond to you?
If so, then the answer is: maybe. If your ISP doesn't block outgoing
TCP port 25 connections, then you should be able to make SMTP
connections
to other sites, to send them your email. (If your ISP blocks this
port,
then the answer is: no.)
However, sites that receive your connections may choose whether they're
willing to accept your mail. Your mail may be considered "spam",
either
by virtue of its content, or by virtue of your connection metadata (how
your IP address resolves to a DNS hostname, whether your IP address is
part of a dynamically allocated residential block, and so on).
Some sites, I've been told, may even attempt to make an SMTP connection
to the registered MX host for your sender's domain, and if they can't
make such a connection, they may consider your mail to be spam.
Also, what good is a one-way email connection to the world? How are
you going to carry on a conversation with someone if you're the only
one able to send messages?
That kind of sounds like the very essence of spam, doesn't it?