电子邮件地址中允许哪些字符？ [英] What characters are allowed in an email address?

问题描述

我不是要求完整的电子邮件验证。

I'm not asking about full email validation.

我只想知道在 user-name 和服务器电子邮件地址的部分。这可能是过于简单的，也许电子邮件地址可以采取其他形式，但我不在乎。我只是问这个简单的形式： user-name @ server （例如[e-mail]），并允许两部分的字符。 / p>

I just want to know what are allowed characters in user-name and server parts of email address. This may be oversimplified, maybe email adresses can take other forms, but I don't care. I'm asking about only this simple form: user-name@server (e.g. [e-mail]) and allowed characters in both parts.

推荐答案

请参阅 RFC 5322：Internet邮件格式，在较小程度上， RFC 5321：简单邮件传输协议。

See RFC 5322: Internet Message Format and, to a lesser extent, RFC 5321: Simple Mail Transfer Protocol.

RFC 822 还包括电子邮件地址，但主要涉及其结构：

RFC 822 also covers email addresses, but it deals mostly with its structure:

 addr-spec   =  local-part "@" domain        ; global address     
 local-part  =  word *("." word)             ; uninterpreted
                                             ; case-preserved

 domain      =  sub-domain *("." sub-domain)     
 sub-domain  =  domain-ref / domain-literal     
 domain-ref  =  atom                         ; symbolic reference

和往常一样，维基百科有一个体面的关于电子邮件地址的文章：

And as usual, Wikipedia has a decent article on email addresses:

电子邮件地址的本地部分可以使用以下任何ASCII字符：

The local-part of the email address may use any of these ASCII characters:

• 大写和小写拉丁字母 A 到 Z 和 a 到 z ;


• 数字 0 至 9 ;


• 特殊字符！＃$％&'* + - / =？^ _`{|}〜;


• dot 。，前提是它不是第一个或最后一个字符，除非引用，并且还提供它不会连续出现，除非引用（例如 John..Doe @ example.com 不允许，但John..Doe@ example.com 被允许）;


• 空格和（），：;<> @ [\] 字符允许有限制（只允许在引用的字符串内部，如下面的段落所述，此外，反斜杠或双引号必须在之前带有反斜杠）;


• 允许任何一个括号中的注释的地方部分;例如 john.smith（comment）@ example.com 和（comment）[e-mail] 都是等效的到 [e-mail] 。

• uppercase and lowercase Latin letters A to Z and a to z;
• digits 0 to 9;
• special characters !#$%&'*+-/=?^_`{|}~;
• dot ., provided that it is not the first or last character unless quoted, and provided also that it does not appear consecutively unless quoted (e.g. [e-mail] is not allowed but "John..Doe"@example.com is allowed);
• space and "(),:;<>@[\] characters are allowed with restrictions (they are only allowed inside a quoted string, as described in the paragraph below, and in addition, a backslash or double-quote must be preceded by a backslash);
• comments are allowed with parentheses at either end of the local-part; e.g. john.smith(comment)@example.com and (comment)[e-mail] are both equivalent to [e-mail].

除了ASCII字符，截至2012年，您可以使用国际以上字符 U + 007F ，编码为UTF-8 。

In addition to ASCII characters, as of 2012 you can use international characters above U+007F, encoded as UTF-8.

要进行验证，请参阅使用正则表达式验证电子邮件地址。

域部分已定义如下：

互联网标准（请求评论）要求组件主机名标签可能只包含ASCII字母 a 通过 z （在一个不区分大小写的方式），数字 0 通过 9 和连字符（ - ）。 RFC 952 中的主机名的原始规范强制标签无法以数字开头或带有连字符，不能以连字符结尾。但是，随后的规范（ RFC 1123 ）允许主机名标签以数字开头。不允许使用其他符号，标点符号或空格。

The Internet standards (Request for Comments) for protocols mandate that component hostname labels may contain only the ASCII letters a through z (in a case-insensitive manner), the digits 0 through 9, and the hyphen (-). The original specification of hostnames in RFC 952, mandated that labels could not start with a digit or with a hyphen, and must not end with a hyphen. However, a subsequent specification (RFC 1123) permitted hostname labels to start with digits. No other symbols, punctuation characters, or blank spaces are permitted.

这篇关于电子邮件地址中允许哪些字符？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！