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mailbox full." In addition to preventing resource abuse on the part of subscribers, this also helps mitigate possible damaging effects of mail bombing by malicious people on the
Internet. We believe that a 10 MB quota is quite generous, especially considering over a 28.8 modem using very high quality line speeds and no network bottlenecks, one could expect to take over an hour to download the contents of a 10 MB mailbox.
434:
In addition to authentication and mailbox location, the mail delivery agent also knows about mailbox quotas which we impose on our subscribers. If the current mailbox size is over the quota for that user, the default being 10 MB, then the message is bounced back to the MTA with reason, "User npc,
280:
While the above definition for Local-part is relatively permissive, for maximum interoperability, a host that expects to receive mail SHOULD avoid defining mailboxes where the Local-part requires (or uses) the Quoted-string form or where the Local-part is
161:(POP): a method that is most suitable for reading messages from a single client computer. Usually messages are removed from the server mailbox after retrieval. Anyway, the master copy of a message is the one in the local mailbox.
275:
extension of SMTP it is also possible to use non-ASCII characters. Some common sense is needed when creating new mailbox names, in order to avoid common pitfalls. In the words of RFC 5321, very wary of imposing restrictions:
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Mailboxes have a size limit, either determined implicitly by available memory, or after quota definitions for that mailbox or folders thereof. Besides administrative trivia, quota limits help mitigate
220:
Any kind of database can be used to store email messages. However, some standardization has resulted in several well-known file formats to allow access to a given mailbox by different
167:(IMAP): designed to retrieve messages from multiple clients by allowing remote management of the server mailbox. Master copies stay on the server, but a copy can be saved locally.
196:
into the server's local mailbox, which, for remote users, is a remote mailbox that they own on that server. IMAP clients can copy, move, and delete messages in remote mailboxes.
177:: messages are served to a user's browser in a server-defined format. Master copies stay on the server, possibly in the original format, which may be downloadable.
181:
IMAP and webmail can go along with each other more or less seamlessly. POP, if configured to leave messages on server, can be compatible with them.
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It further exemplifies that some sites may choose to print mail on a printer and deliver the output to the addressee's desk, much like a traditional
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retrieves messages from one or more mailboxes. The database (file, directory, storage system) in which the client stores the messages is called the
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Some names are known to cause troubles, possibly because they conflict with names used internally by (some parts of) the mail software, including
184:
Internet message format, currently defined by RFC 5322, dates back to 1982 (RFC 822). That is what POP and IMAP clients expect to retrieve.
327:(dot) provided that it is not the first or last character, and provided also that it does not appear two or more times consecutively (e.g.
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134:. Usually, anyone can send messages to a mailbox while only authenticated users can read or delete from their own mailboxes. An
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as a character string that identifies a user to whom mail will be sent or a location into which mail will be deposited. The term
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The local-part may be up to 64 characters long and, in theory, is case-sensitive. It can consist of either a sequence of
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The names "postmaster", "abuse", and others correspond to well-known roles and functions, and are required to be valid.
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is a newer specification that provides for storing all messages in a directory tree, with one file for each message.
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A mailbox receives mail. It is a 'conceptual entity' that does not necessarily pertain to file storage.
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271:(described below) or a quoted string, which can also contain spaces and special characters. Using
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is sometimes used to refer to an address that does not correspond to a definitive mail store.
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symbol. Its format is formally specified by RFC 5322 and RFC 5321. It is often the
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581:"A list of reserved usernames to avoid vanity URL collision with resource paths"
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70:. However, not all email addresses correspond to a storage facility. The term
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Nick
Christenson; Tim Bosserman; David Beckemeyer (December 9, 1997).
403:, P. Resnick (Ed.), The Internet Society (October 2008), Section 3.4 (
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The following characters may appear in a local-part without quoting:
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A mailbox name is the first part of an email address, also known as
386:, J. Klensin, The Internet Society (October 2008), Section 2.3.11 (
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is the original technique of storing all messages in a single file,
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of the recipient on the mail server or in the destination domain.
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419:"A Highly Scalable Electronic Mail Service Using Open Systems"
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may be applied to reach end recipients from such addresses.
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chokes on them. A number of lists exist, for example on
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Uppercase and lowercase
English letters (a–z, A–Z), and
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537:
Mailbox names for common services, roles and functions
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An IMAP extension for quota was standardized in 1997.
319:! # $ % & ' * + - / = ? ^ _ ` { | } ~
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refers to that depository. In that sense, the terms
54:messages are delivered. It is the equivalent of a
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224:. There are two kinds of widely used formats:
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192:Messages sent to a mailbox are written by a
492:SMTP Extension for Internationalized Email
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27:Destination to which emails are delivered
485:Jiankang YAO; Wei MAO (February 2012).
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130:Access to a mailbox is controlled by a
108:RFC 5322 defines a mailbox as follows:
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154:protocols to retrieve messages are:
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165:Internet Message Access Protocol
256:; that is, the part before the
447:John G. Myers (January 1997).
66:A mailbox is identified by an
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384:Simple Mail Transfer Protocol
105:can be used interchangeably.
346:, or because the underlying
304:sequences if using SMTPUTF8
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605:Michael Mahemoff (2011).
534:Dave Crocker (May 1997).
607:"Reserved username list"
487:"The SMTPUTF8 Extension"
80:Electronic mailing lists
401:Internet Message Format
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286:John Klensin, RFC 5321
86:are typical examples.
58:in the postal system.
579:Casey O'Hara (2011).
450:IMAP4 QUOTA extension
405:Address Specification
89:RFC 5321, defines an
159:Post Office Protocol
544:. sec. 3,4,5.
388:Mailbox and Address
194:mail delivery agent
36:electronic mailbox
499:. sec. 3.2.
373:ISO/IEC 2382:2015
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68:email address
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44:email mailbox
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590:December 12,
588:. Retrieved
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564:December 12,
562:. Retrieved
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519:December 12,
517:. Retrieved
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428:December 12,
426:. Retrieved
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344:mail filters
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188:Write access
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136:email client
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126:Email client
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317:Characters
146:Read access
62:Definitions
399:RFC 5322,
382:RFC 5321,
358:References
323:Character
254:local-part
207:email bomb
200:Size quota
56:letter box
209:attacks.
48:e-mailbox
40:email box
637:Category
284:—
273:SMTPUTF8
262:username
150:Popular
307:Digits
235:Maildir
171:Webmail
103:address
99:mailbox
95:mailbox
32:mailbox
585:GitHub
423:USENIX
352:GitHub
120:Access
34:(also
643:Email
302:UTF-8
173:over
592:2015
566:2015
559:2142
542:IETF
521:2015
514:6531
497:IETF
472:2087
455:IETF
430:2015
229:mbox
175:HTTP
101:and
82:and
556:RFC
546:doi
511:RFC
501:doi
469:RFC
459:doi
311:to
114:fax
639::
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366:^
354:.
330:).
142:.
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42:,
38:,
30:A
609:.
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568:.
548::
523:.
503::
474:.
461::
407:)
390:)
325:.
313:9
309:0
258:@
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