lisp/gnus/pop3.el

   1 ;;; pop3.el --- Post Office Protocol (RFC 1460) interface
   2
   3 ;; Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
   4 ;;   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   5
   6 ;; Author: Richard L. Pieri <ratinox@peorth.gweep.net>
   7 ;; Maintainer: FSF
   8 ;; Keywords: mail
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Commentary:
  26
  27 ;; Most of the standard Post Office Protocol version 3 (RFC 1460) commands
  28 ;; are implemented.  The LIST command has not been implemented due to lack
  29 ;; of actual usefulness.
  30 ;; The optional POP3 command TOP has not been implemented.
  31
  32 ;; This program was inspired by Kyle E. Jones's vm-pop program.
  33
  34 ;;; Code:
  35
  36 (require 'mail-utils)
  37 (defvar parse-time-months)
  38
  39 (defgroup pop3 nil
  40   "Post Office Protocol."
  41   :group 'mail
  42   :group 'mail-source)
  43
  44 (defcustom pop3-maildrop (or (user-login-name)
  45                              (getenv "LOGNAME")
  46                              (getenv "USER"))
  47   "*POP3 maildrop."
  48   :version "22.1" ;; Oort Gnus
  49   :type 'string
  50   :group 'pop3)
  51
  52 (defcustom pop3-mailhost (or (getenv "MAILHOST") ;; nil -> mismatch
  53                              "pop3")
  54   "*POP3 mailhost."
  55   :version "22.1" ;; Oort Gnus
  56   :type 'string
  57   :group 'pop3)
  58
  59 (defcustom pop3-port 110
  60   "*POP3 port."
  61   :version "22.1" ;; Oort Gnus
  62   :type 'number
  63   :group 'pop3)
  64
  65 (defcustom pop3-password-required t
  66   "*Non-nil if a password is required when connecting to POP server."
  67   :version "22.1" ;; Oort Gnus
  68   :type 'boolean
  69   :group 'pop3)
  70
  71 ;; Should this be customizable?
  72 (defvar pop3-password nil
  73   "*Password to use when connecting to POP server.")
  74
  75 (defcustom pop3-authentication-scheme 'pass
  76   "*POP3 authentication scheme.
  77 Defaults to `pass', for the standard USER/PASS authentication.  The other
  78 valid value is 'apop'."
  79   :type '(choice (const :tag "Normal user/password" pass)
  80                  (const :tag "APOP" apop))
  81   :version "22.1" ;; Oort Gnus
  82   :group 'pop3)
  83
  84 (defcustom pop3-leave-mail-on-server nil
  85   "*Non-nil if the mail is to be left on the POP server after fetching.
  86
  87 If `pop3-leave-mail-on-server' is non-nil the mail is to be left
  88 on the POP server after fetching.  Note that POP servers maintain
  89 no state information between sessions, so what the client
  90 believes is there and what is actually there may not match up.
  91 If they do not, then you may get duplicate mails or the whole
  92 thing can fall apart and leave you with a corrupt mailbox."
  93   ;; We can't use the UILD support from XEmacs mail-lib or cvs.m17n.org:
  94   ;; http://thread.gmane.org/v9lld8fml4.fsf@marauder.physik.uni-ulm.de
  95   ;; http://thread.gmane.org/b9yy8hzy9ej.fsf@jpl.org
  96   ;; Any volunteer to re-implement this?
  97   :version "22.1" ;; Oort Gnus
  98   :type 'boolean
  99   :group 'pop3)
 100
 101 (defcustom pop3-display-message-size-flag t
 102   "*If non-nil, display the size of the message that is being fetched."
 103   :version "22.1" ;; Oort Gnus
 104   :type 'boolean
 105   :group 'pop3)
 106
 107 (defvar pop3-timestamp nil
 108   "Timestamp returned when initially connected to the POP server.
 109 Used for APOP authentication.")
 110
 111 (defvar pop3-read-point nil)
 112 (defvar pop3-debug nil)
 113
 114 ;; Borrowed from nnheader-accept-process-output in nnheader.el.  See the
 115 ;; comments there for explanations about the values.
 116
 117 (eval-and-compile
 118   (if (and (fboundp 'nnheader-accept-process-output)
 119            (boundp 'nnheader-read-timeout))
 120       (defalias 'pop3-accept-process-output 'nnheader-accept-process-output)
 121     ;; Borrowed from `nnheader.el':
 122     (defvar pop3-read-timeout
 123       (if (string-match "windows-nt\\|os/2\\|emx\\|cygwin"
 124                         (symbol-name system-type))
 125           1.0
 126         0.01)
 127       "How long pop3 should wait between checking for the end of output.
 128 Shorter values mean quicker response, but are more CPU intensive.")
 129     (defun pop3-accept-process-output (process)
 130       (accept-process-output
 131        process
 132        (truncate pop3-read-timeout)
 133        (truncate (* (- pop3-read-timeout
 134                        (truncate pop3-read-timeout))
 135                     1000))))))
 136
 137 (defun pop3-movemail (&optional crashbox)
 138   "Transfer contents of a maildrop to the specified CRASHBOX."
 139   (or crashbox (setq crashbox (expand-file-name "~/.crashbox")))
 140   (let* ((process (pop3-open-server pop3-mailhost pop3-port))
 141          (crashbuf (get-buffer-create " *pop3-retr*"))
 142          (n 1)
 143          message-count
 144          message-sizes
 145          (pop3-password pop3-password))
 146     ;; for debugging only
 147     (if pop3-debug (switch-to-buffer (process-buffer process)))
 148     ;; query for password
 149     (if (and pop3-password-required (not pop3-password))
 150         (setq pop3-password
 151               (read-passwd (format "Password for %s: " pop3-maildrop))))
 152     (cond ((equal 'apop pop3-authentication-scheme)
 153            (pop3-apop process pop3-maildrop))
 154           ((equal 'pass pop3-authentication-scheme)
 155            (pop3-user process pop3-maildrop)
 156            (pop3-pass process))
 157           (t (error "Invalid POP3 authentication scheme")))
 158     (setq message-count (car (pop3-stat process)))
 159     (when (and pop3-display-message-size-flag
 160                (> message-count 0))
 161       (setq message-sizes (pop3-list process)))
 162     (unwind-protect
 163         (while (<= n message-count)
 164           (if pop3-display-message-size-flag
 165               (message "Retrieving message %d of %d from %s... (%.1fk)"
 166                        n message-count pop3-mailhost
 167                        (/ (cdr (assoc n message-sizes))
 168                           1024.0))
 169             (message "Retrieving message %d of %d from %s..."
 170                      n message-count pop3-mailhost))
 171           (pop3-retr process n crashbuf)
 172           (save-excursion
 173             (set-buffer crashbuf)
 174             (let ((coding-system-for-write 'binary))
 175               (write-region (point-min) (point-max) crashbox t 'nomesg))
 176             (set-buffer (process-buffer process))
 177             (while (> (buffer-size) 5000)
 178               (goto-char (point-min))
 179               (forward-line 50)
 180               (delete-region (point-min) (point))))
 181           (unless pop3-leave-mail-on-server
 182             (pop3-dele process n))
 183           (setq n (+ 1 n))
 184           (pop3-accept-process-output process))
 185       (when (and pop3-leave-mail-on-server
 186                  (> n 1))
 187         (message "pop3.el doesn't support UIDL.  Setting `pop3-leave-mail-on-server'
 188 to %s might not give the result you'd expect." pop3-leave-mail-on-server)
 189         (sit-for 1))
 190       (pop3-quit process))
 191     (kill-buffer crashbuf))
 192   t)
 193
 194 (defun pop3-get-message-count ()
 195   "Return the number of messages in the maildrop."
 196   (let* ((process (pop3-open-server pop3-mailhost pop3-port))
 197          message-count
 198          (pop3-password pop3-password))
 199     ;; for debugging only
 200     (if pop3-debug (switch-to-buffer (process-buffer process)))
 201     ;; query for password
 202     (if (and pop3-password-required (not pop3-password))
 203         (setq pop3-password
 204               (read-passwd (format "Password for %s: " pop3-maildrop))))
 205     (cond ((equal 'apop pop3-authentication-scheme)
 206            (pop3-apop process pop3-maildrop))
 207           ((equal 'pass pop3-authentication-scheme)
 208            (pop3-user process pop3-maildrop)
 209            (pop3-pass process))
 210           (t (error "Invalid POP3 authentication scheme")))
 211     (setq message-count (car (pop3-stat process)))
 212     (pop3-quit process)
 213     message-count))
 214
 215 (autoload 'open-tls-stream "tls")
 216 (autoload 'starttls-open-stream "starttls")
 217 (autoload 'starttls-negotiate "starttls") ; avoid warning
 218
 219 (defcustom pop3-stream-type nil
 220   "*Transport security type for POP3 connexions.
 221 This may be either nil (plain connexion), `ssl' (use an
 222 SSL/TSL-secured stream) or `starttls' (use the starttls mechanism
 223 to turn on TLS security after opening the stream).  However, if
 224 this is nil, `ssl' is assumed for connexions to port
 225 995 (pop3s)."
 226   :version "23.1" ;; No Gnus
 227   :group 'pop3
 228   :type '(choice (const :tag "Plain" nil)
 229                  (const :tag "SSL/TLS" ssl)
 230                  (const starttls)))
 231
 232 (defun pop3-open-server (mailhost port)
 233   "Open TCP connection to MAILHOST on PORT.
 234 Returns the process associated with the connection."
 235   (let ((coding-system-for-read 'binary)
 236         (coding-system-for-write 'binary)
 237         process)
 238     (save-excursion
 239       (set-buffer (get-buffer-create (concat " trace of POP session to "
 240                                              mailhost)))
 241       (erase-buffer)
 242       (setq pop3-read-point (point-min))
 243       (setq process
 244             (cond
 245              ((or (eq pop3-stream-type 'ssl)
 246                   (and (not pop3-stream-type) (member port '(995 "pop3s"))))
 247               ;; gnutls-cli, openssl don't accept service names
 248               (if (or (equal port "pop3s")
 249                       (null port))
 250                   (setq port 995))
 251               (let ((process (open-tls-stream "POP" (current-buffer)
 252                                               mailhost port)))
 253                 (when process
 254                   ;; There's a load of info printed that needs deleting.
 255                   (let ((again 't))
 256                     ;; repeat until
 257                     ;; - either we received the +OK line
 258                     ;; - or accept-process-output timed out without getting
 259                     ;;   anything
 260                     (while (and again
 261                                 (setq again (memq (process-status process)
 262                                                   '(open run))))
 263                       (setq again (pop3-accept-process-output process))
 264                       (goto-char (point-max))
 265                       (forward-line -1)
 266                       (cond ((looking-at "\\+OK")
 267                              (setq again nil)
 268                              (delete-region (point-min) (point)))
 269                             ((not again)
 270                              (pop3-quit process)
 271                              (error "POP SSL connexion failed")))))
 272                   process)))
 273              ((eq pop3-stream-type 'starttls)
 274               ;; gnutls-cli, openssl don't accept service names
 275               (if (equal port "pop3")
 276                   (setq port 110))
 277               (let ((process (starttls-open-stream "POP" (current-buffer)
 278                                                    mailhost (or port 110))))
 279                 (pop3-send-command process "STLS")
 280                 (let ((response (pop3-read-response process t)))
 281                   (if (and response (string-match "+OK" response))
 282                       (starttls-negotiate process)
 283                     (pop3-quit process)
 284                     (error "POP server doesn't support starttls")))
 285                 process))
 286              (t
 287               (open-network-stream "POP" (current-buffer) mailhost port))))
 288       (let ((response (pop3-read-response process t)))
 289         (setq pop3-timestamp
 290               (substring response (or (string-match "<" response) 0)
 291                          (+ 1 (or (string-match ">" response) -1)))))
 292       process)))
 293
 294 ;; Support functions
 295
 296 (defun pop3-process-filter (process output)
 297   (save-excursion
 298     (set-buffer (process-buffer process))
 299     (goto-char (point-max))
 300     (insert output)))
 301
 302 (defun pop3-send-command (process command)
 303   (set-buffer (process-buffer process))
 304   (goto-char (point-max))
 305   ;; (if (= (aref command 0) ?P)
 306   ;;     (insert "PASS <omitted>\r\n")
 307   ;;   (insert command "\r\n"))
 308   (setq pop3-read-point (point))
 309   (goto-char (point-max))
 310   (process-send-string process (concat command "\r\n")))
 311
 312 (defun pop3-read-response (process &optional return)
 313   "Read the response from the server.
 314 Return the response string if optional second argument is non-nil."
 315   (let ((case-fold-search nil)
 316         match-end)
 317     (save-excursion
 318       (set-buffer (process-buffer process))
 319       (goto-char pop3-read-point)
 320       (while (and (memq (process-status process) '(open run))
 321                   (not (search-forward "\r\n" nil t)))
 322         (pop3-accept-process-output process)
 323         (goto-char pop3-read-point))
 324       (setq match-end (point))
 325       (goto-char pop3-read-point)
 326       (if (looking-at "-ERR")
 327           (error "%s" (buffer-substring (point) (- match-end 2)))
 328         (if (not (looking-at "+OK"))
 329             (progn (setq pop3-read-point match-end) nil)
 330           (setq pop3-read-point match-end)
 331           (if return
 332               (buffer-substring (point) match-end)
 333             t)
 334           )))))
 335
 336 (defun pop3-clean-region (start end)
 337   (setq end (set-marker (make-marker) end))
 338   (save-excursion
 339     (goto-char start)
 340     (while (and (< (point) end) (search-forward "\r\n" end t))
 341       (replace-match "\n" t t))
 342     (goto-char start)
 343     (while (and (< (point) end) (re-search-forward "^\\." end t))
 344       (replace-match "" t t)
 345       (forward-char)))
 346   (set-marker end nil))
 347
 348 ;; Copied from message-make-date.
 349 (defun pop3-make-date (&optional now)
 350   "Make a valid date header.
 351 If NOW, use that time instead."
 352   (require 'parse-time)
 353   (let* ((now (or now (current-time)))
 354          (zone (nth 8 (decode-time now)))
 355          (sign "+"))
 356     (when (< zone 0)
 357       (setq sign "-")
 358       (setq zone (- zone)))
 359     (concat
 360      (format-time-string "%d" now)
 361      ;; The month name of the %b spec is locale-specific.  Pfff.
 362      (format " %s "
 363              (capitalize (car (rassoc (nth 4 (decode-time now))
 364                                       parse-time-months))))
 365      (format-time-string "%Y %H:%M:%S " now)
 366      ;; We do all of this because XEmacs doesn't have the %z spec.
 367      (format "%s%02d%02d" sign (/ zone 3600) (/ (% zone 3600) 60)))))
 368
 369 (defun pop3-munge-message-separator (start end)
 370   "Check to see if a message separator exists.  If not, generate one."
 371   (save-excursion
 372     (save-restriction
 373       (narrow-to-region start end)
 374       (goto-char (point-min))
 375       (if (not (or (looking-at "From .?") ; Unix mail
 376                    (looking-at "\001\001\001\001\n") ; MMDF
 377                    (looking-at "BABYL OPTIONS:") ; Babyl
 378                    ))
 379           (let* ((from (mail-strip-quoted-names (mail-fetch-field "From")))
 380                  (tdate (mail-fetch-field "Date"))
 381                  (date (split-string (or (and tdate
 382                                               (not (string= "" tdate))
 383                                               tdate)
 384                                          (pop3-make-date))
 385                                      " "))
 386                  (From_))
 387             ;; sample date formats I have seen
 388             ;; Date: Tue, 9 Jul 1996 09:04:21 -0400 (EDT)
 389             ;; Date: 08 Jul 1996 23:22:24 -0400
 390             ;; should be
 391             ;; Tue Jul 9 09:04:21 1996
 392
 393             ;; Fixme: This should use timezone on the date field contents.
 394             (setq date
 395                   (cond ((not date)
 396                          "Tue Jan 1 00:00:0 1900")
 397                         ((string-match "[A-Z]" (nth 0 date))
 398                          (format "%s %s %s %s %s"
 399                                  (nth 0 date) (nth 2 date) (nth 1 date)
 400                                  (nth 4 date) (nth 3 date)))
 401                         (t
 402                          ;; this really needs to be better but I don't feel
 403                          ;; like writing a date to day converter.
 404                          (format "Sun %s %s %s %s"
 405                                  (nth 1 date) (nth 0 date)
 406                                  (nth 3 date) (nth 2 date)))
 407                         ))
 408             (setq From_ (format "\nFrom %s  %s\n" from date))
 409             (while (string-match "," From_)
 410               (setq From_ (concat (substring From_ 0 (match-beginning 0))
 411                                   (substring From_ (match-end 0)))))
 412             (goto-char (point-min))
 413             (insert From_)
 414             (if (search-forward "\n\n" nil t)
 415                 nil
 416               (goto-char (point-max))
 417               (insert "\n"))
 418             (narrow-to-region (point) (point-max))
 419             (let ((size (- (point-max) (point-min))))
 420               (goto-char (point-min))
 421               (widen)
 422               (forward-line -1)
 423               (insert (format "Content-Length: %s\n" size)))
 424             )))))
 425
 426 ;; The Command Set
 427
 428 ;; AUTHORIZATION STATE
 429
 430 (defun pop3-user (process user)
 431   "Send USER information to POP3 server."
 432   (pop3-send-command process (format "USER %s" user))
 433   (let ((response (pop3-read-response process t)))
 434     (if (not (and response (string-match "+OK" response)))
 435         (error "USER %s not valid" user))))
 436
 437 (defun pop3-pass (process)
 438   "Send authentication information to the server."
 439   (pop3-send-command process (format "PASS %s" pop3-password))
 440   (let ((response (pop3-read-response process t)))
 441     (if (not (and response (string-match "+OK" response)))
 442         (pop3-quit process))))
 443
 444 (defun pop3-apop (process user)
 445   "Send alternate authentication information to the server."
 446   (let ((pass pop3-password))
 447     (if (and pop3-password-required (not pass))
 448         (setq pass
 449               (read-passwd (format "Password for %s: " pop3-maildrop))))
 450     (if pass
 451         (let ((hash (md5 (concat pop3-timestamp pass) nil nil 'binary)))
 452           (pop3-send-command process (format "APOP %s %s" user hash))
 453           (let ((response (pop3-read-response process t)))
 454             (if (not (and response (string-match "+OK" response)))
 455                 (pop3-quit process)))))
 456     ))
 457
 458 ;; TRANSACTION STATE
 459
 460 (defun pop3-stat (process)
 461   "Return the number of messages in the maildrop and the maildrop's size."
 462   (pop3-send-command process "STAT")
 463   (let ((response (pop3-read-response process t)))
 464     (list (string-to-number (nth 1 (split-string response " ")))
 465           (string-to-number (nth 2 (split-string response " "))))
 466     ))
 467
 468 (defun pop3-list (process &optional msg)
 469   "If MSG is nil, return an alist of (MESSAGE-ID . SIZE) pairs.
 470 Otherwise, return the size of the message-id MSG"
 471   (pop3-send-command process (if msg
 472                                  (format "LIST %d" msg)
 473                                "LIST"))
 474   (let ((response (pop3-read-response process t)))
 475     (if msg
 476         (string-to-number (nth 2 (split-string response " ")))
 477       (let ((start pop3-read-point) end)
 478         (save-excursion
 479           (set-buffer (process-buffer process))
 480           (while (not (re-search-forward "^\\.\r\n" nil t))
 481             (pop3-accept-process-output process)
 482             (goto-char start))
 483           (setq pop3-read-point (point-marker))
 484           (goto-char (match-beginning 0))
 485           (setq end (point-marker))
 486           (mapcar #'(lambda (s) (let ((split (split-string s " ")))
 487                                   (cons (string-to-number (nth 0 split))
 488                                         (string-to-number (nth 1 split)))))
 489                   (delete "" (split-string (buffer-substring start end)
 490                                            "\r\n"))))))))
 491
 492 (defun pop3-retr (process msg crashbuf)
 493   "Retrieve message-id MSG to buffer CRASHBUF."
 494   (pop3-send-command process (format "RETR %s" msg))
 495   (pop3-read-response process)
 496   (let ((start pop3-read-point) end)
 497     (save-excursion
 498       (set-buffer (process-buffer process))
 499       (while (not (re-search-forward "^\\.\r\n" nil t))
 500         (pop3-accept-process-output process)
 501         (goto-char start))
 502       (setq pop3-read-point (point-marker))
 503       ;; this code does not seem to work for some POP servers...
 504       ;; and I cannot figure out why not.
 505       ;;      (goto-char (match-beginning 0))
 506       ;;      (backward-char 2)
 507       ;;      (if (not (looking-at "\r\n"))
 508       ;;          (insert "\r\n"))
 509       ;;      (re-search-forward "\\.\r\n")
 510       (goto-char (match-beginning 0))
 511       (setq end (point-marker))
 512       (pop3-clean-region start end)
 513       (pop3-munge-message-separator start end)
 514       (save-excursion
 515         (set-buffer crashbuf)
 516         (erase-buffer))
 517       (copy-to-buffer crashbuf start end)
 518       (delete-region start end)
 519       )))
 520
 521 (defun pop3-dele (process msg)
 522   "Mark message-id MSG as deleted."
 523   (pop3-send-command process (format "DELE %s" msg))
 524   (pop3-read-response process))
 525
 526 (defun pop3-noop (process msg)
 527   "No-operation."
 528   (pop3-send-command process "NOOP")
 529   (pop3-read-response process))
 530
 531 (defun pop3-last (process)
 532   "Return highest accessed message-id number for the session."
 533   (pop3-send-command process "LAST")
 534   (let ((response (pop3-read-response process t)))
 535     (string-to-number (nth 1 (split-string response " ")))
 536     ))
 537
 538 (defun pop3-rset (process)
 539   "Remove all delete marks from current maildrop."
 540   (pop3-send-command process "RSET")
 541   (pop3-read-response process))
 542
 543 ;; UPDATE
 544
 545 (defun pop3-quit (process)
 546   "Close connection to POP3 server.
 547 Tell server to remove all messages marked as deleted, unlock the maildrop,
 548 and close the connection."
 549   (pop3-send-command process "QUIT")
 550   (pop3-read-response process t)
 551   (if process
 552       (save-excursion
 553         (set-buffer (process-buffer process))
 554         (goto-char (point-max))
 555         (delete-process process))))
 556 \f
 557 ;; Summary of POP3 (Post Office Protocol version 3) commands and responses
 558
 559 ;;; AUTHORIZATION STATE
 560
 561 ;; Initial TCP connection
 562 ;; Arguments: none
 563 ;; Restrictions: none
 564 ;; Possible responses:
 565 ;;  +OK [POP3 server ready]
 566
 567 ;; USER name
 568 ;; Arguments: a server specific user-id (required)
 569 ;; Restrictions: authorization state [after unsuccessful USER or PASS
 570 ;; Possible responses:
 571 ;;  +OK [valid user-id]
 572 ;;  -ERR [invalid user-id]
 573
 574 ;; PASS string
 575 ;; Arguments: a server/user-id specific password (required)
 576 ;; Restrictions: authorization state, after successful USER
 577 ;; Possible responses:
 578 ;;  +OK [maildrop locked and ready]
 579 ;;  -ERR [invalid password]
 580 ;;  -ERR [unable to lock maildrop]
 581
 582 ;; STLS      (RFC 2595)
 583 ;; Arguments: none
 584 ;; Restrictions: Only permitted in AUTHORIZATION state.
 585 ;; Possible responses:
 586 ;;  +OK
 587 ;;  -ERR
 588
 589 ;;; TRANSACTION STATE
 590
 591 ;; STAT
 592 ;; Arguments: none
 593 ;; Restrictions: transaction state
 594 ;; Possible responses:
 595 ;;  +OK nn mm [# of messages, size of maildrop]
 596
 597 ;; LIST [msg]
 598 ;; Arguments: a message-id (optional)
 599 ;; Restrictions: transaction state; msg must not be deleted
 600 ;; Possible responses:
 601 ;;  +OK [scan listing follows]
 602 ;;  -ERR [no such message]
 603
 604 ;; RETR msg
 605 ;; Arguments: a message-id (required)
 606 ;; Restrictions: transaction state; msg must not be deleted
 607 ;; Possible responses:
 608 ;;  +OK [message contents follow]
 609 ;;  -ERR [no such message]
 610
 611 ;; DELE msg
 612 ;; Arguments: a message-id (required)
 613 ;; Restrictions: transaction state; msg must not be deleted
 614 ;; Possible responses:
 615 ;;  +OK [message deleted]
 616 ;;  -ERR [no such message]
 617
 618 ;; NOOP
 619 ;; Arguments: none
 620 ;; Restrictions: transaction state
 621 ;; Possible responses:
 622 ;;  +OK
 623
 624 ;; LAST
 625 ;; Arguments: none
 626 ;; Restrictions: transaction state
 627 ;; Possible responses:
 628 ;;  +OK nn [highest numbered message accessed]
 629
 630 ;; RSET
 631 ;; Arguments: none
 632 ;; Restrictions: transaction state
 633 ;; Possible responses:
 634 ;;  +OK [all delete marks removed]
 635
 636 ;;; UPDATE STATE
 637
 638 ;; QUIT
 639 ;; Arguments: none
 640 ;; Restrictions: none
 641 ;; Possible responses:
 642 ;;  +OK [TCP connection closed]
 643
 644 (provide 'pop3)
 645
 646 ;; arch-tag: 2facc142-1d74-498e-82af-4659b64cac12
 647 ;;; pop3.el ends here