On 23/12/2019 20:59, Roger Hayter wrote:
The Natural Philosopher wrote:

On 23/12/2019 00:27, Roger Hayter wrote:
The Natural Philosopher wrote:

On 22/12/2019 13:57, John Rumm wrote:
On 21/12/2019 21:39, Tim Streater wrote:
In article , The Natural Philosopher
wrote:

On 21/12/2019 19:11, John Rumm wrote:
On 21/12/2019 16:21, The Natural Philosopher wrote:
On 21/12/2019 15:45, John Rumm wrote:
I think most would be comfortable with the concept of a "SMTP
server", a "POP3 server" and an "IMAP server" as being fair
description a software process running on a server that implements
the server end of those protocols.

They might be, but the established terminology is of an SMTP relay,
because it *serves* nothing.

If it sits there with an open rendezvous port, waiting for a client
to connect, then its a server.

No, it isnt.

A router does that.

No, routers route packets.

For some reason I can't see TNP's reply which you quoted. However I am
somewhat surprised by it since I had thought he had a better grip on
networking related stuff and hence would know that a router is layer 3
device with no concept of end to end transport steam concepts like ports
and sockets.


Every router I have had has a management interface. It listens to
telnelt ssh or http.
Does that make it a server?

Yes. In a rather trivial, but undeniable, sense.


I wonder why we call it a 'router' then.
Because that is its main job.

Not a 'server'
It is a server too though.

And a mail relay a mail relay, not a mail server.

A mail relay is an SMTP server and also an SMTP client. If it also
provides a local (in the connectivity rather than geographical sense)
mail service then it will have, or share data with, a POP3 or IMAP (or
proprietary eg MS) server.


But mail *relays* do NOT, and have not since pretty much the days when
the internet took off, because the primary meed for a mail *server* is
massive storage and resilience, whereas a mail relay is the ability to
handle many connections and good connectivity and anti-spam security.

Very different hardware and software requirements.





--
"First, find out who are the people you can not criticise. They are your
oppressors."
- George Orwell