380:— an optional list of hosts and a required destination-mailbox. When the list of hosts existed, it served as a source-route, indicating that each host had to relay the mail to the next host on the list. Otherwise, in the case of insufficient destination-information but where the server knew the correct destination, it could take the responsibility to deliver the message by responding as follows:
258:(SPF), the domain-name in the envelope sender remains subject to policy restrictions. Therefore, SPF generally disallows plain message-forwarding. In case of forwarding, the email is being sent from the forwarding server, which is not authorized to send emails for the original sender's domain. So the SPF will fail.
346:
and any attachment. Note that including all the headers discloses much information about the message, such as the servers that transmitted it and any client-tag added on the mailbox. The recipient of a message forwarded this way may be able to open the attached message and reply to it seamlessly.
519:
The term "virtual users" refers to email users who never log on a mail-server system and only access their mailboxes using remote clients. A mail-server program may work for both virtual and regular users, or it may require minor modifications to take advantage of the fact that virtual users
524:. The latter circumstance allows the server program to implement some features more easily, as it does not have to obey system-access restrictions. The same principles of operations apply. However, virtual users have more difficulty in accessing their configuration files, for good or ill.
426:
made source-routing unnecessary. In 1989, RFC 1123 recommended accepting source-routing only for backward-compatibility. At that point, plain message forwarding became the recommended action for alias-expansion. In 2008, RFC 5321 still mentions that "systems
327:.) The recipient of a message forwarded this way may still be able to reply to the original message; the ability to do so depends on the presence of original headers and may imply manually copying and pasting the relevant destination addresses.
434:
as needed", taking into consideration that not doing so might inadvertently disclose sensitive information. Actually, plain message-forwarding can be conveniently used for alias expansion within the same server or a set of coordinated servers.
51:
Email forwarding can also redirect mail going to a certain address and send it to one or more other addresses. Vice versa, email items going to several different addresses can converge via forwarding to end up in a single address in-box.
765:
A Mediator forwards a message through a re-posting process. The
Mediator shares some functionality with basic MTA relaying, but has greater flexibility in both addressing and content than is available to
176:
When users change their email address, or have several addresses, the user or an administrator may set up forwarding from these addresses, if still valid, to a single current one, in order to avoid losing
687:
of the message. The envelope is lost when the message is delivered, although some of its fields may be saved by the receiving server in the message's headers. In particular, the envelope holds the
902:
48:, used for mail since long before electronic communications, has no specific technical meaning, but it implies that the email has been moved "forward" to a new destination.
419:
implied that the "envelope sender" information could not remain in its original form during forwarding. Thus RFC 821 did not originally allow plain message-forwarding.
507:
so it could impersonate any user whose mail it had to manage. On the other hand, users can access their own individual mail-files and configuration files, including
170:; there are also separate providers of mail forwarding services. This allows users to have an email address that does not change if they change mailbox provider.
156:
in email addresses. An organization may forward messages intended for a given role to the address of the person(s) currently functioning in that role or office.
415:(envelope sender) as a message got relayed from one SMTP server to another. Even if the system discouraged the use of source-routing, dynamically building the
511:. Client programs may assist in editing the server configuration-files of a given user, thereby causing some confusion as to what role each program plays.
470:, which have become a source of many security problems. Formerly only trusted users could utilize the command-line switch for setting the envelope sender,
946:
may refuse the message according to RFC 7208. In other words, one cannot formally distinguish plain message-forwarding from illegal domain-name abuse.
232:(which report a failure delivering a message to any list- subscriber) will not reach the author of a message. However, annoying misconfigured
129:, it is becoming increasingly difficult to reliably forward mail across different domains, and some recommend avoiding it if at all possible.
335:
243:
tout-court serves for mailing-lists. When additional modifications to the message are carried out, so as to rather resemble the action of a
266:
message-forwarding may break SPF even if they do not implement SPF themselves, i.e. they neither apply SPF checks nor publish SPF records.
618:, if the same term weren't used at the beginning of the same subsection with the opposite meaning. As a contributor to RFC 5321 agreed,
1090:
621:
1057:
1006:
Interoperability Issues between Domain-based
Message Authentication, Reporting, and Conformance (DMARC) and Indirect Email Flows
1010:
736:
981:
Plain message forwarding may disclose the final destination-address irrespectively of the user's intention. See sections 7.7
458:
files, which can store the target email-addresses for given users. This kind of server-based forwarding is sometimes called
262:
redirection complies with SPF as long as the relevant servers share a consistent configuration. Mail servers that practice
836:
553:
871:
466:
to automatically perform forwarding or replying actions immediately after receiving. Forward files can also contain
493:
118:
as a synonym for server-based email-forwarding to different recipients. Protocol engineers sometimes use the term
612:
the key difference between handling aliases (Section 3.9.1) and forwarding (this subsection) is the change to the
167:
580:
538:
267:
255:
221:
354:
from the points of view of the envelope-sender and of the recipient(s). The message identity also changes.
569:
1094:
504:
166:
facilities provide facilities to forward mail to another email address such as a mailbox at the user's
239:
Typically, plain message-forwarding does alias-expansion, while proper message-forwarding, also named
1024:
750:
284:
197:
which Email client software usually displays: it represents a field used in the early stages of the
163:
60:
56:
489:
485:
367:
999:
Franck Martin; Eliot Lear; Tim
Draegen; Elizabeth Zwicky; Kurt Andersen, eds. (September 2016).
481:
1053:
1000:
1065:
1097:
originated in the 1970s, they did not become widely used until networks became quite common.
1014:
740:
497:
463:
316:
726:
631:
563:
315:
quotes the message below the main text of the new message, and usually preserves original
244:
220:
can sometimes mean re-sending the message and also rewriting the "envelope sender" field.
187:
782:
283:
Client forwarding can take place automatically using a non-interactive client such as a
55:
Email users and administrators of email systems use the same term when speaking of both
27:
Mechanism by which a mail server sends the emails of one of its users to another address
1113:
692:
229:
206:
100:
291:
in that it keeps the same message-identity. Concerns about the envelope-sender apply.
1107:
80:
38:
467:
308:
287:. Although the retrieval agent uses a client protocol, this forwarding resembles
17:
1027:
1004:
778:
753:
730:
659:
614:." That wording, new w.r.t. RFC 2821, could be interpreted as the definition of
575:
548:
543:
533:
400:
390:
377:
111:) provide a typical example of server-based forwarding to different recipients.
84:
72:
663:
558:
126:
969:
655:
501:
423:
88:
968:
MX record has been introduced with RFC 974. See the historical section in
186:
Plain message-forwarding changes the envelope recipient(s) and leaves the
451:
300:
33:
generically refers to the operation of re-sending a previously delivered
1019:
745:
343:
205:
header. This field holds the address to which mail-systems must send
194:
34:
500:
which run on the same machine. The sendmail daemon used to run with
190:
field untouched. The "envelope sender" field does not equate to the
95:
messages without changing any part of their envelopes. By contrast,
87:
for the corresponding class of addresses. A domain may also define
270:
provides for a generic forwarding mechanism compatible with SPF.
680:
626:
447:
198:
889:
883:
877:
484:
architectures in the 1990s. Therefore, the distinction between
492:
seems necessarily forced. The original distinction contrasted
107:
it by changing some envelope addresses. ~/.forward files (see
477:; some systems disabled this feature for security reasons.
319:
as well as a choice of selected headers (e.g. the original
837:"How does email forwarding affect authentication result?"
658:
of the relevant domain usually publishes the name of the
342:) that contains the full original message, including all
804:"Mailbox Names for Common Services, Roles and Functions"
251:
becomes deceptive and remailing seems more appropriate.
228:
that performs remailing to each list address. That way,
224:
furnish a typical example. Authors submit messages to a
407:
The concept at that time envisaged the elements of the
133:
Uses of server-based forwarding to different recipients
874:
209:— reporting delivery-failure (or success) — if any.
1080:
to describe its action on the envelope sender data.
862:
860:
858:
896:
374:for each recipient, in the form of, for example,
910:must not plainly forward a message from domain
897:{\displaystyle {\ce {\mathit {A->B->C}}}}
350:This kind of forwarding actually constitutes a
152:, and similar names can appear to the left of
8:
983:Information Disclosure in Message Forwarding
598:
596:
114:Email administrators sometimes use the term
679:of a message is the data transmitted in an
918:, unless it controls either the policy of
358:Historical development of email forwarding
41:to one or more different email addresses.
1018:
876:
875:
873:
744:
662:. Otherwise the domain name must have an
462:. One can configure some email-program
201:protocol, and subsequently saved as the
622:"English terms for forwarded addresses"
592:
1068:mentions no restrictions in using the
930:publishes an SPF policy that prevents
866:Consider the following forward path:
450:implementation in the early 1980s was
1093:range from the early 1990s. Although
108:
7:
1064:The current (version 8.708 of 2006)
683:transaction before transmitting the
643:a fuzzy (non-technical) term in SMTP
610:is used ambiguously. It notes that "
480:Email predates the formalization of
75:(the part appearing to the right of
431:remove the return path and rebuild
247:submitting a new message, the term
173:Multiple, or discontinued addresses
970:MX record#History of fallback to A
942:applies sender's policy-checking,
99:can deliver a message to a user's
25:
783:"Users Don't Like Forwarded Spam"
520:frequently share the same system
279:Automated client-based forwarding
122:to refer to a forwarding server.
376:@USC-ISIE.ARPA, @USC-ISIF.ARPA:
955:See the note in section 6.2.7
886:
880:
295:Manual client-based forwarding
236:autoreplies do reach authors.
1:
1050:TCP/IP Network Administration
411:(source route) moving to the
397:251Usernotlocal;willforwardto
364:Simple Mail Transfer Protocol
91:; they have no mailboxes and
957:Explicit path specification
554:Email subject abbreviations
307:forward a message using an
182:Forwarding versus remailing
1130:
1072:switch, and uses the verb
732:Internet Mail Architecture
725:Dave Crocker (July 2009).
1052:. O'Reilly. p. 606.
620:Tony Finch (2008-11-03).
566:(MUA) a.k.a. email client
168:Internet Service Provider
422:The introduction of the
382:
370:in 1982, provided for a
222:Electronic mailing lists
581:Sender Rewriting Scheme
539:Electronic mailing list
274:Client-based forwarding
268:Sender Rewriting Scheme
256:Sender Policy Framework
212:By contrast, the terms
67:Server-based forwarding
1095:remote procedure calls
1066:sendmail documentation
898:
806:, 1997, mentions also
606:of RFC 5321, the term
570:Message transfer agent
899:
454:, which provided for
83:) defines the target
1048:Hunt, Craig (2002).
922:or the filtering of
872:
496:and user-controlled
338:attachment (of type
285:mail retrieval agent
1013:. sec. 3.2.1.
164:domain name hosting
159:Pseudonym-addresses
1089:The book dates in
894:
707:) and one or more
368:Jonathan B. Postel
1091:client-server-faq
987:Trace Information
891:
885:
879:
602:In section 3.9.2
289:server forwarding
18:E-mail forwarding
16:(Redirected from
1121:
1098:
1087:
1081:
1071:
1063:
1045:
1039:
1038:
1036:
1034:
1022:
1020:10.17487/RFC7960
996:
990:
979:
973:
966:
960:
953:
947:
903:
901:
900:
895:
893:
892:
864:
853:
852:
850:
848:
843:. 6 January 2023
833:
827:
800:
794:
793:
791:
790:
775:
769:
768:
762:
760:
748:
746:10.17487/RFC5598
722:
716:
673:
667:
652:
646:
645:
640:
639:
630:. Archived from
600:
510:
476:
457:
441:
403:
396:
393:
386:
379:
31:Email forwarding
21:
1129:
1128:
1124:
1123:
1122:
1120:
1119:
1118:
1104:
1103:
1102:
1101:
1088:
1084:
1069:
1060:
1047:
1046:
1042:
1032:
1030:
998:
997:
993:
980:
976:
967:
963:
954:
950:
870:
869:
865:
856:
846:
844:
835:
834:
830:
801:
797:
788:
786:
777:
776:
772:
758:
756:
739:. sec. 5.
724:
723:
719:
674:
670:
653:
649:
637:
635:
619:
601:
594:
589:
564:Mail user agent
530:
517:
508:
471:
455:
444:
439:
405:
404:
398:
394:
388:
384:
375:
360:
297:
281:
276:
245:Mail User Agent
230:bounce messages
207:bounce messages
188:envelope sender
184:
135:
97:primary servers
69:
28:
23:
22:
15:
12:
11:
5:
1127:
1125:
1117:
1116:
1106:
1105:
1100:
1099:
1082:
1058:
1040:
991:
974:
961:
948:
905:
904:
888:
882:
854:
828:
795:
781:(2008-10-15).
770:
717:
693:bounce address
668:
647:
591:
590:
588:
585:
584:
583:
578:
573:
567:
561:
556:
551:
546:
541:
536:
529:
526:
516:
513:
460:dot-forwarding
446:The reference
443:
437:
383:
359:
356:
340:message/rfc822
296:
293:
280:
277:
275:
272:
218:redistribution
183:
180:
179:
178:
174:
171:
160:
157:
139:
138:Role-addresses
134:
131:
89:backup servers
68:
65:
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1126:
1115:
1112:
1111:
1109:
1096:
1092:
1086:
1083:
1079:
1075:
1067:
1061:
1059:0-596-00334-X
1055:
1051:
1044:
1041:
1029:
1026:
1021:
1016:
1012:
1008:
1007:
1002:
995:
992:
988:
984:
978:
975:
971:
965:
962:
958:
952:
949:
945:
941:
937:
933:
929:
926:. Indeed, if
925:
921:
917:
913:
909:
868:
867:
863:
861:
859:
855:
842:
838:
832:
829:
825:
821:
817:
813:
809:
805:
799:
796:
784:
780:
774:
771:
767:
755:
752:
747:
742:
738:
734:
733:
728:
721:
718:
714:
710:
706:
702:
698:
694:
690:
686:
682:
678:
672:
669:
665:
661:
657:
651:
648:
644:
634:on 2008-12-11
633:
629:
628:
623:
617:
613:
609:
605:
599:
597:
593:
586:
582:
579:
577:
574:
571:
568:
565:
562:
560:
557:
555:
552:
550:
547:
545:
542:
540:
537:
535:
532:
531:
527:
525:
523:
515:Virtual users
514:
512:
506:
503:
499:
495:
491:
487:
483:
482:client–server
478:
475:
469:
468:shell scripts
465:
461:
453:
449:
438:
436:
433:
430:
425:
420:
418:
414:
410:
401:
391:
381:
378:
373:
369:
365:
357:
355:
353:
348:
345:
341:
337:
333:
332:as attachment
328:
326:
322:
318:
314:
311:. Forwarding
310:
306:
302:
294:
292:
290:
286:
278:
273:
271:
269:
265:
261:
257:
252:
250:
246:
242:
237:
235:
231:
227:
223:
219:
215:
210:
208:
204:
200:
196:
193:
189:
181:
175:
172:
169:
165:
161:
158:
155:
151:
147:
143:
140:
137:
136:
132:
130:
128:
123:
121:
117:
112:
110:
106:
102:
98:
94:
90:
86:
82:
81:email address
78:
74:
66:
64:
62:
58:
53:
49:
47:
42:
40:
39:email address
36:
32:
19:
1085:
1077:
1076:rather than
1073:
1049:
1043:
1031:. Retrieved
1005:
994:
989:in RFC 5321.
986:
982:
977:
964:
956:
951:
943:
939:
938:s name, and
935:
931:
927:
923:
919:
915:
911:
907:
845:. Retrieved
840:
831:
823:
819:
815:
811:
807:
803:
798:
787:. Retrieved
773:
764:
757:. Retrieved
731:
720:
712:
708:
704:
700:
696:
688:
684:
676:
671:
654:The primary
650:
642:
636:. Retrieved
632:the original
625:
615:
611:
607:
603:
549:Email Letter
521:
518:
479:
473:
459:
445:
432:
428:
421:
416:
412:
409:forward-path
408:
406:
372:forward-path
371:
363:
361:
351:
349:
339:
331:
329:
324:
320:
312:
309:email client
304:
298:
288:
282:
264:inter-domain
263:
260:Intra domain
259:
253:
248:
240:
238:
233:
225:
217:
213:
211:
202:
191:
185:
153:
149:
145:
141:
124:
119:
115:
113:
104:
96:
92:
76:
70:
63:forwarding.
61:client-based
57:server-based
54:
50:
45:
43:
30:
29:
934:from using
826:, and more.
779:John Levine
727:"Mediators"
711:(including
689:Return-Path
660:mail server
576:Email storm
544:Email alias
534:Chain email
417:return-path
413:return-path
334:prepares a
330:Forwarding
317:attachments
203:Return-Path
125:Because of
116:redirection
73:domain name
985:, and 4.4
959:of RFC 822
914:to domain
802:RFC 2142,
789:2008-11-07
785:. CircleID
709:recipients
699:argument,
664:IP address
638:2008-11-07
616:forwarding
608:forwarding
559:Email spam
509:~/.forward
505:privileges
456:~/.forward
440:~/.forward
249:forwarding
241:forwarding
150:postmaster
46:forwarding
887:⟶
881:⟶
824:webmaster
808:marketing
697:MAIL FROM
656:MX record
424:MX record
362:RFC 821,
352:remailing
226:reflector
214:remailing
177:messages.
85:server(s)
44:The term
1108:Category
1078:override
1033:14 March
847:16 March
841:ProDMARC
820:security
759:19 March
701:mailfrom
691:(a.k.a.
677:envelope
528:See also
498:programs
452:sendmail
325:Reply-To
305:manually
301:end-user
234:vacation
120:Mediator
1001:"Alias"
906:Domain
812:support
685:content
494:daemons
464:filters
387:RCPTTO:
344:headers
254:In the
105:forward
103:and/or
101:mailbox
93:forward
1056:
490:server
486:client
313:inline
195:header
79:in an
37:to an
1114:Email
816:abuse
766:MTAs.
705:mfrom
703:, or
587:Notes
572:(MTA)
442:files
366:, by
162:Most
146:sales
109:below
35:email
1054:ISBN
1035:2017
1028:7960
1011:IETF
849:2023
761:2013
754:5598
737:IETF
715:'s).
681:SMTP
675:The
627:IETF
604:List
502:root
488:and
448:SMTP
402:>
399:<
392:>
389:<
336:MIME
323:and
321:From
303:can
199:SMTP
192:From
142:info
127:spam
71:The
59:and
1074:set
1025:RFC
1015:doi
751:RFC
741:doi
713:Bcc
474:arg
472:-f
429:may
299:An
216:or
1110::
1070:-f
1023:.
1009:.
1003:.
936:A'
857:^
839:.
822:,
818:,
814:,
810:,
763:.
749:.
735:.
729:.
695:,
641:.
624:.
595:^
522:id
395:R:
385:S:
148:,
144:,
1062:.
1037:.
1017::
972:.
944:C
940:C
932:B
928:A
924:C
920:A
916:C
912:A
908:B
890:C
884:B
878:A
851:.
792:.
743::
666:.
154:@
77:@
20:)
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.