Re: [gentoo-user] tips on running a mail server in a cheap vps provider run but not-so-trusty admins?

[Caveman Al Toraboran]

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Friday, August 21, 2020 11:37 PM, Grant Taylor <gtaylor@×××××××××××××××××××××.net> wrote:

> SMTP may not be the best, but I do think that it has some merits.
> Merits that the previously mentioned HTTP/2 alternative misses.

not a major point but just to clarify a thing.

i think it's unfair to look at SMTP as a single
thing that compares against HTTP*.  because while
HTTP* is a single-ish thing, SMTP is several
things.  i.e. SMTP is at least 2 parts:

1. resource exchange layer where people are
   defined as some kind of URL (e.g.
   name@×××.zone) and attachments are base64-ed
   text balls referred to by some numbers in
   RFC822.  This part overlaps with HTTP*.  let's
   call this "RESXCH_SERVER".

2. the part where it defines how to process
   the exchanged resources (e.g. safe storage,
   routing, etc).  this part is beyond HTTP*'s
   scope, and is the "web app" scope.  let's call
   this "RESUSE_SERVER"

of course, email still doesn't work with those 2
parts, because you need a way to get mails to your
email client, so you end up using POP or IMAP.
now, this --itself-- is also two parts:

1. resource exchange layer to send resources to
   users.  which also overlaps with HTTP* (again).
   let's call this "RESXCH_CLIENT".

2. the part where it defines how the mail client
   to treat the resources.  let's call this
   "RESUSE_CLIENT".


> Why add an additional protocol to the stack?
>
> TCP / SMTP is two layers.
>
> TCP / HTTP / $Email-protocol-de-jure is three layers.
>
> UDP / HTTP / $Email-protocol-de-jusre is three layers.
>
> Why introduce an additional layer?

i disagree.  i think this is more like it about
the current email system:

RESXCH_SERVER / RESUSE_SERVER / RESXCH_CLIENT / RESUSE_CLIENT

it's 4 different layers to exchange mail between
people.

but if we plug HTTP* in the mix, it because only 3
different layers:

HTTP* / RESUSE_SERVER / HTTP* / RESUSE_CLIENT

and it is even nicer for when HTTP* is plugged,
because it is also the protocol used for most of
internet's traffic (web browsing).

so basically total expected number of
protocols/layers used in the universe, per second,
will be much less if we, on planet earth, use a
mail system that uses HTTP* instead of RESXCH_*.