最优雅的方法是使用. net的内置方法。

这些方法:

都是经过考验的。我在自己的专业项目中使用了这些方法。 内部使用正则表达式，这是可靠和快速的。 由微软为c#编写。没有必要做重复的工作。 返回bool类型的结果。True表示邮件有效。

适用于。net 4.5及以上版本的用户

将此引用添加到项目中:

System.ComponentModel.DataAnnotations

现在你可以使用下面的代码:

(new EmailAddressAttribute().IsValid("youremailhere@test.test"));

使用实例

下面是一些需要声明的方法:

protected List<string> GetRecipients() // Gets recipients from TextBox named `TxtRecipients`
{
    List<string> MethodResult = null;

    try
    {
        List<string> Recipients = TxtRecipients.Text.Replace(",",";").Replace(" ", "").Split(';').ToList();

        List<string> RecipientsCleaned = new List<string>();

        foreach (string Recipient in RecipientsCleaned)
        {
            if (!String.IsNullOrWhiteSpace(Recipient))
            {
                RecipientsNoBlanks.Add(Recipient);

            }

        }

        MethodResult = RecipientsNoBlanks;

    }
    catch//(Exception ex)
    {
        //ex.HandleException();
    }

    return MethodResult;

}


public static bool IsValidEmailAddresses(List<string> recipients)
{
    List<string> InvalidAddresses = GetInvalidEmailAddresses(recipients);

    return InvalidAddresses != null && InvalidAddresses.Count == 0;

}

public static List<string> GetInvalidEmailAddresses(List<string> recipients)
{
    List<string> MethodResult = null;

    try
    {
        List<string> InvalidEmailAddresses = new List<string>();

        foreach (string Recipient in recipients)
        {
            if (!(new EmailAddressAttribute().IsValid(Recipient)) && !InvalidEmailAddresses.Contains(Recipient))
            {
                InvalidEmailAddresses.Add(Recipient);

            }

        }

        MethodResult = InvalidEmailAddresses;

    }
    catch//(Exception ex)
    {
        //ex.HandleException();

    }

    return MethodResult;

}

.．.以及演示它们的代码:

List<string> Recipients = GetRecipients();

bool IsValidEmailAddresses = IsValidEmailAddresses(Recipients);

if (IsValidEmailAddresses)
{
    //Emails are valid. Your code here

}
else
{
    StringBuilder sb = new StringBuilder();

    sb.Append("The following addresses are invalid:");

    List<string> InvalidEmails = GetInvalidEmailAddresses(Recipients);

    foreach (string InvalidEmail in InvalidEmails)
    {
        sb.Append("\n" + InvalidEmail);

    }

    MessageBox.Show(sb.ToString());

}

另外，这个例子:

扩展超出规范，因为一个字符串用于包含0，一个或多个由分号分隔的电子邮件地址; 清楚地演示了如何使用EmailAddressAttribute对象的IsValid方法。

对于.Net 4.5以下版本的用户，可以选择

对于.Net 4.5不可用的情况，我使用以下解决方案:

具体来说，我使用:

public static bool IsValidEmailAddress(string emailAddress)
{
    bool MethodResult = false;

    try
    {
        MailAddress m = new MailAddress(emailAddress);

        MethodResult = m.Address == emailAddress;

    }
    catch //(Exception ex)
    {
        //ex.HandleException();

    }

    return MethodResult;

}

public static List<string> GetInvalidEmailAddresses(List<string> recipients)
{
    List<string> MethodResult = null;

    try
    {
        List<string> InvalidEmailAddresses = new List<string>();

        foreach (string Recipient in recipients)
        {
            if (!IsValidEmail(Recipient) && !InvalidEmailAddresses.Contains(Recipient))
            {
                InvalidEmailAddresses.Add(Recipient);

            }

        }

        MethodResult = InvalidEmailAddresses;

    }
    catch //(Exception ex)
    {
        //ex.HandleException();

    }

    return MethodResult;

}

There are a lot of strong answers here. However, I recommend that we take a step back. @Cogwheel answers the question https://stackoverflow.com/a/1374644/388267. Nevertheless, it could be costly in a bulk validation scenario, if many of the email address being validated are invalid. I suggest that we employ a bit of logic before we enter into his try-catch block. I know that the following code could be written using RegEx but that could be costly for new developers to understand. This is my twopence worth:

    public static bool IsEmail(this string input)
    {
        if (string.IsNullOrWhiteSpace(input)) return false;

        // MUST CONTAIN ONE AND ONLY ONE @
        var atCount = input.Count(c => c == '@');
        if (atCount != 1) return false;

        // MUST CONTAIN PERIOD
        if (!input.Contains(".")) return false;

        // @ MUST OCCUR BEFORE LAST PERIOD
        var indexOfAt = input.IndexOf("@", StringComparison.Ordinal);
        var lastIndexOfPeriod = input.LastIndexOf(".", StringComparison.Ordinal);
        var atBeforeLastPeriod = lastIndexOfPeriod > indexOfAt;
        if (!atBeforeLastPeriod) return false;

        // CODE FROM COGWHEEL'S ANSWER: https://stackoverflow.com/a/1374644/388267 
        try
        {
            var addr = new System.Net.Mail.MailAddress(input);
            return addr.Address == input;
        }
        catch
        {
            return false;
        }
    }

老实说，在产品代码中，我所做的最好的事情就是检查@符号。

我从来没有在一个地方完全验证电子邮件。你知道我怎么判断它是否有效吗?如果发送出去了。如果没有，那就糟了，如果有，生活就好了。这就是我需要知道的。

我最终使用了这个正则表达式，因为它成功地验证了逗号、注释、Unicode字符和IP(v4)域地址。

有效地址为:

“@example。org (评论)test@example。org тест@example。org ტესტი@example。org test@[192.168 . 1章1段]

 public const string REGEX_EMAIL = @"^(((\([\w!#$%&'*+\/=?^_`{|}~-]*\))?[^<>()[\]\\.,;:\s@\""]+(\.[^<>()[\]\\.,;:\s@\""]+)*)|(\"".+\""))(\([\w!#$%&'*+\/=?^_`{|}~-]*\))?@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))$";

我经常用这个来验证电子邮件，它就像一个魅力。这验证了电子邮件必须在@之前至少有一个字符，并且在“”之前至少有一个字符。

public static bool ValidateEmail(string value, bool required, int minLength, int maxLength)
        {
           value = value.Trim();
           if (required == false && value == "") return true;
           if (required && value == "") return false;
           if (value.Length < minLength || value.Length > maxLength) return false;

           //Email must have at least one character before an @, and at least one character before the .
           int index = value.IndexOf('@');
           if (index < 1 || value.LastIndexOf('.') < index + 2) return false;
           return true;
        }

如果你正在使用FluentValidation，你可以写一些像这样简单的东西:

public cass User
{
    public string Email { get; set; }
}

public class UserValidator : AbstractValidator<User>
{
    public UserValidator()
    {
        RuleFor(x => x.Email).EmailAddress().WithMessage("The text entered is not a valid email address.");
    }
}

// Validates an user. 
var validationResult = new UserValidator().Validate(new User { Email = "açflkdj" });

// This will return false, since the user email is not valid.
bool userIsValid = validationResult.IsValid;