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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.
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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,
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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
150:(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.
264:
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
209:
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
156:(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.
185:
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.
166:: 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.
170:
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
331:
Some names are known to cause troubles, possibly because they conflict with names used internally by (some parts of) the mail software, including
173:
Internet message format, currently defined by RFC 5322, dates back to 1982 (RFC 822). That is what POP and IMAP clients expect to retrieve.
316:(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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123:. 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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530:
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A mailbox receives mail. It is a 'conceptual entity' that does not necessarily pertain to file storage.
260:(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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570:"A list of reserved usernames to avoid vanity URL collision with resource paths"
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59:. 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).
392:, 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
375:, 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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408:"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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Mailbox names for common services, roles and functions
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An IMAP extension for quota was standardized in 1997.
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308:! # $ % & ' * + - / = ? ^ _ ` { | } ~
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refers to that depository. In that sense, the terms
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43:messages are delivered. It is the equivalent of a
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213:. There are two kinds of widely used formats:
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181:Messages sent to a mailbox are written by a
481:SMTP Extension for Internationalized Email
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16:Destination to which emails are delivered
474:Jiankang YAO; Wei MAO (February 2012).
119:Access to a mailbox is controlled by a
97:RFC 5322 defines a mailbox as follows:
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143:protocols to retrieve messages are:
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154:Internet Message Access Protocol
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436:John G. Myers (January 1997).
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55:A mailbox is identified by an
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39:) is the destination to which
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373:Simple Mail Transfer Protocol
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94:can be used interchangeably.
335:, or because the underlying
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293:sequences if using SMTPUTF8
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594:Michael Mahemoff (2011).
523:Dave Crocker (May 1997).
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596:"Reserved username list"
476:"The SMTPUTF8 Extension"
69:Electronic mailing lists
390:Internet Message Format
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275:John Klensin, RFC 5321
75:are typical examples.
47:in the postal system.
568:Casey O'Hara (2011).
439:IMAP4 QUOTA extension
394:Address Specification
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78:RFC 5321, defines an
148:Post Office Protocol
533:. sec. 3,4,5.
377:Mailbox and Address
183:mail delivery agent
25:electronic mailbox
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362:ISO/IEC 2382:2015
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113:Main article:
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80:email address
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73:email aliases
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57:email address
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33:email mailbox
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579:December 12,
577:. Retrieved
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553:December 12,
551:. Retrieved
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508:December 12,
506:. Retrieved
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417:December 12,
415:. Retrieved
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333:mail filters
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115:Email client
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306:Characters
135:Read access
51:Definitions
388:RFC 5322,
371:RFC 5321,
347:References
312:Character
243:local-part
196:email bomb
189:Size quota
45:letter box
198:attacks.
37:e-mailbox
29:email box
626:Category
273:—
262:SMTPUTF8
251:username
139:Popular
296:Digits
224:Maildir
160:Webmail
92:address
88:mailbox
84:mailbox
21:mailbox
574:GitHub
412:USENIX
341:GitHub
109:Access
23:(also
632:Email
291:UTF-8
162:over
581:2015
555:2015
548:2142
531:IETF
510:2015
503:6531
486:IETF
461:2087
444:IETF
419:2015
218:mbox
164:HTTP
90:and
71:and
545:RFC
535:doi
500:RFC
490:doi
458:RFC
448:doi
300:to
103:fax
628::
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498:.
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355:^
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