MAIL FROM:<grey@cat.baz>                                  \ envelope
RCPT TO:<john@example.com>                                / ("koperta")
DATA
From: Greebo <grey@cat.baz>               \               \
To: John Q. Public <john@example.com>     | headers       | contents
Date: Mon, 13 Jan 2025 03:00:00 +0100     | (nagłówki)    | ("zawartość")
Subject: Khhhhhhhhhhhhh                   /               |
                                                          |
KhIIIIsss!                                ] body (treść)  /
.

 ____    ┌─────┐      ┌─────┐      ┌─────┐      ┌─────┐      ┌─────┐    .------. 
(mail) → │ MUA │-→-→-→│ MSA │-→-→-→│ MTA │-→-→-→│ MTA │-→-→-→│ MDA │ → (skrzynka)
 ‾‾‾‾    └─────┘ SMTP └─────┘ SMTP └─────┘ SMTP └─────┘ SMTP └─────┘    `------‘

                \____/       \_________________/       \____/ 
               wysłanie          przekazanie         dostarcznie
             (submission)          (relay)           (delivery)

 .------.    ┌─────┐           ┌─────────┐
(skrzynka) ← │ MAA │  ←  ←  ←  │ MRA/MUA │
 `------‘    └─────┘ POP3/IMAP └─────────┘

220 example.org ESMTP
EHLO sub.domain.baz
250-example.org hello sub.domain.baz
250-AUTH LOGIN PLAIN
250 8BITMIME
AUTH PLAIN
334 
AHVzZXIAcGFzc3dvcmQ=
235 Authentication succeeded
MAIL FROM:<user@example.org>
250 OK
RCPT TO:<friend@example.org>
250 Accepted
RCPT TO:<mellon@doriath.mi>
250 Accepted
DATA
354 Enter message, ending with "." on a line by itself
From: <user@example.org>
Date: Mon, 13 Jan 2025 00:00:00 +0000

Zorg
.
250 OK id=1tXOtg-007aSz-0m
QUIT
221 example.org closing connection

foo search subject "SK2"
baz search subject "sieci"
* SEARCH 2 5 7 10
foo OK SEARCH completed
* SEARCH 5 7 10 12
baz OK SEARCH completed

A CAPABILITY
* CAPABILITY IMAP4rev1 IDLE UNSELECT
A OK CAPABILITY completed
B LOGIN user@example.org qwerty
B OK [CAPABILITY IMAP4 IMAP4rev1 IDLE UNSELECT] User logged in
C LIST "" *
* LIST (\HasNoChildren) "/" "INBOX"
* LIST (\HasNoChildren \Drafts) "/" "Drafts"
* LIST (\HasNoChildren \Junk) "/" "Junk"
* LIST (\HasNoChildren \Sent) "/" "Sent"
* LIST (\HasNoChildren \Trash) "/" "Trash"
C OK LIST completed
D SELECT "INBOX"
* FLAGS (\Answered \Deleted \Draft \Flagged \Seen)
* 50 EXISTS
* 0 RECENT
* OK [UNSEEN 48]
* OK [UIDNEXT 85]
D OK [READ-WRITE] Completed
E SEARCH UNSEEN
* SEARCH 48 50
E OK SEARCH completed
F UID SEARCH UNSEEN
* SEARCH 82 84
F OK completed
G SEARCH SINCE 1-JAN-2025
* SEARCH 46 47 48 49 50
G OK SEARCH completed
H FETCH 49:50 BODY.PEEK[HEADER.FIELDS (SUBJECT)]
* 49 FETCH (BODY[HEADER.FIELDS (SUBJECT)] {30}
Subject: Meeting on Monday

)
* 50 FETCH (BODY[HEADER.FIELDS (SUBJECT)] {33}
Subject: Re: Meeting on Monday

)
H OK FETCH completed
I FETCH 50 BODY[]
* 50 FETCH (BODY[] {715}
Return-Path: 
Received: from mx.doriath.mi
…
Subject: Re: Meeting on Monday

Ok, pasuje.

)
I OK FETCH completed
J IDLE
+ idling
* 51 EXISTS
DONE
J OK IDLE completed
K FETCH 51 (INTERNALDATE BODYSTRUCTURE ENVELOPE)
* 51 FETCH (INTERNA… 
…

Return-path: <user+abc =example=example.org@gmail.com>
Received: from mail-yb1-xb2c.google.com ([2607:f8b0:4864:20::b2c])
    by mail.example.org with esmtps  (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256
    (Exim 4.96)
    (envelope-from <user+abc_=example=example.org@gmail.com)
    id 1tWaLw-005ThV-0Q
    for user@example.org;
    Sat, 11 Jan 2025 13:12:33 +0100
Received: by mail-yb1-xb2c.google.com with SMTP id 3f1490d57ef6-e3c8ae3a3b2so3989188276.0
        for <user@example.org>; Sat, 11 Jan 2025 04:12:31 -0800 (PST)
Received: by 2002:a05:6918:2743:b0:29e:22a8:4a84 with SMTP id kl3csp727682ysb;
        Sat, 11 Jan 2025 04:11:26 -0800 (PST)
Received: from mail-sor-f41.google.com (mail-sor-f41.google.com. [209.85.220.41])
        by mx.google.com with SMTPS id 4fb4d7f45d1cf-5d98fe87a9fsor2448019a12.0.2025.01.11.04.11.25
        for <littlejimmy@example.com>
        (Google Transport Security);
        Sat, 11 Jan 2025 04:11:25 -0800 (PST)
Received: by 2002:a05:7412:4:b0:139:5231:8a71 with SMTP id 4csp730573rdb;
        Sat, 11 Jan 2025 04:11:23 -0800 (PST)
Received: from mail22.atl91.mcsv.net (mail22.atl91.mcsv.net. [198.2.130.22])
        by mx.google.com with ESMTPS id 3f1490d57ef6-e55be2b386esi2450299276.511.2025.01.11.04.11.22
        for <smith@example.com>
        (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256);
        Sat, 11 Jan 2025 04:11:22 -0800 (PST)
Received: from mail22.atl91.mcsv.net ([127.0.0.1])
        by localhost (mail22.atl91.mcsv.net [127.0.0.1]) (amavisd-new, port 10026)
        with ESMTP id vi1BlmqBCQOU; Sat, 11 Jan 2025 12:11:22 +0000
Received: from localhost (localhost [127.0.0.1])
        by mail22.atl91.mcsv.net (Postfix) with ESMTP id BC4FCE0BA6
        for <smith@example.com>; Sat, 11 Jan 2025 12:11:20 +0000

… poprzednie nagłówki …
Content-Type: multipart/alternate; boundary="oddzielacz"

--oddzielacz
Content-Type: text/plain

Przyjdzie o **jedenastej** wieczorem.
--oddzielacz
Content-Type: text/html

<html><body><p>Przyjdzie o <b>jedenastej</b> wieczorem.</p></body></html>
--oddzielacz--

… poprzednie nagłówki …
… inne nagłówki …
Content-Type: multipart/mixed; boundary="fikusny_separator"

--fikusny_separator
Content-Type: text/plain

Zobacz ten obrazek!
--fikusny_separator
Content-Type: image/png
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="mail.png"

iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAAAAAA6mKC9AAAATElEQVQY04WOOQ7AQAwCZ1b+/5dJ
ETvHpgjyISFAGN5YCNgjrP7GURBzioYgzEHcQ9mIFMRLHykg2AtU+0bVxCNq8am+oe6OJ8yf5QDW
ShMmZmKfpQAAAABJRU5ErkJggg==
--fikusny_separator--

… poprzednie nagłówki …
Content-Type: multipart/mixed; boundary="a"

--a
Content-Type: multipart/alternative; boundary="b"

--b
Content-Type: text/plain

Zobacz ten obrazek!
[IMG]
--b
Content-Type: multipart/related; boundary="c"

--c
Content-Type: text/html

<html><body><p>Zobacz ten obrazek!</p>
<p><img src="cid:my-mail-img""></p></body></html>
--c
Content-Type: image/png
Content-Transfer-Encoding: base64
Content-ID: <my-mail-img>

iVBORw0KGgoAAAANSUhEUgAAABAAAAAQCAAAAAA6mKC9AAAATElEQVQY04WOOQ7AQAwCZ1b+/5dJ
ETvHpgjyISFAGN5YCNgjrP7GURBzioYgzEHcQ9mIFMRLHykg2AtU+0bVxCNq8am+oe6OJ8yf5QDW
ShMmZmKfpQAAAABJRU5ErkJggg==
--c--
--b--
--a
Content-Type: text/plain
Content-Disposition: attachment; filename="licencja.txt"

kopyrajt 2025
--a--