如何使用正则表达式验证电子邮件地址？

Question

多年来，我一直在慢慢开发一个regular expression来验证大多数电子邮件地址是否正确，假设它们不使用IP地址作为服务器部分。

我在几个PHP程序中使用它，而且它大部分时间都在工作。然而，有时我会被一个在使用它的网站上遇到问题的人联系，最后我不得不做一些调整（最近我意识到我不允许4字符的tld）。

对于验证电子邮件，您所拥有或见过的最佳正则表达式是什么？

我已经看到一些解决方案使用了使用几个较短表达式的函数，但是我宁愿在简单函数中使用一个长的复杂表达式，而不是在更复杂的函数中使用多个短表达式。

Answer 1

不应使用正则表达式验证电子邮件地址。

相反，使用MailAddress类，如下所示：

try {
    address = new MailAddress(address).Address;
} catch(FormatException) {
    //address is invalid
}

MailAddress类使用BNF解析器完全按照RFC822验证地址。

如果您真的想使用regex，here it is：

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