Information AboutE-mail Address |
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An e-mail address identifies a location to which e-mail address (using SMTP or Usenet ) is a string of the form ''jsmith@example.com''. It should be read as "jsmith '''at''' example '''dot''' com". The part before the @ sign is the '''local-part''' of the address, often the Username of the recipient, and the part after the @ sign is the '''domain-part''' which may be a host name or Domain Name which can be looked up in the Domain Name System to find the Mail Transfer Agent or Mail EXchangers (MXs) accepting e-mail for that address. The domain name of an e-mail address is often that of the e-mail service, such as Google's Gmail , Microsoft's Hotmail , etc. The domain name can also be the domain name of the company that the recipient represents, or the domain of the recipient's Personal Site . Earlier forms of e-mail addresses included the somewhat verbose notation required by X.400 , and the UUCP "bang path" notation, in which the address was given in the form of a sequence of computers through which the message should be relayed. This latter was widely used for several years, but was superseded by the generally more convenient SMTP form. Addresses found in the header fields of e-mail should not be considered authoritative, because SMTP has no generally-required mechanisms for Authentication . Forged e-mail addresses are often seen in Spam , Phishing , and many other internet-based scams; this has led to several initiatives which aim to make such forgeries easier to spot. To indicate where the message should go, a user normally types the "display name" of the recipient followed by the address specification surrounded by angled brackets, for example: John Smith . LIMITATIONS The format of Internet e-mail addresses is defined in RFC 2822, which permits them to consist of only a subset of ASCII characters. As defined in RFC 2821, the local-part of an e-mail address has a maximum of 64 characters (although servers are encouraged to not limit themselves to accepting only 64 characters) and the Domain Name a maximum of 255 characters. Unlike everything else in the header, the local-part "MUST BE treated as case sensitive. {Link without Title} However, exploiting the case sensitivity of mailbox local-parts impedes interoperability and is discouraged." Local part is the portion of a mail address before the @ character. This normally identifies a particular mailbox within a site mail system so is not usually of interest to other mail systems. According to RFC 2822, the local-part of the address may use any of these ASCII characters:
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Notwithstanding The Addresses Permitted By These Standards, Some Systems Impose More Restrictions On Email Addresses, Both In Email Addresses Created On The System And In Email Addresses To Which Messages Can Be Sent
| "http://wwwinformationdelightinfo/information/entry/Hotmail" class="copylinks">Hotmail , for example, only allows creation of email addresses using alphanumerics, dot (<code></code>), underscore (<code>_</code>) and hyphen (<code>-</code>), and will not allow sending mail to any email address containing <code>! # $ % / ^ { } ` ~</code> {Link without Title} , as of 11/25/2006 |
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