[ArgumentNullException用于使用NetCore.MailKit发送电子邮件时的地址

Question

我正在使用NetCore.MailKit NuGet软件包来帮助我发送一封电子邮件，其中包含一个链接，以在用户注册时确认其电子邮件。我已经按照他们的Github page上的步骤进行操作，但是，即使设置了发送地址，我的地址也仍然是ArgumentNullException。

错误：

ArgumentNullException: Value cannot be null. (Parameter 'address')
    MimeKit.MailboxAddress..ctor(Encoding encoding, string name, string address)

当使用IEmailService在我的控制器中发送电子邮件时，发生上述错误：

_EmailService.Send("[email protected]", "subject", "message body");

这是我的appsettings.json配置：

  "EmailConfiguration": {
    "Server": "smtp.gmail.com",
    "Port": 587,
    "SenderName": "name",
    "SenderEmail": "[email protected]",
    "SenderPassword": "My gmail password"
  }

这是我在startup.cs中的设置

    services.AddMailKit(optionBuilder =>
    {
        optionBuilder.UseMailKit(new MailKitOptions()
        {
            //get options from sercets.json
            Server = Configuration["Server"],
            Port = Convert.ToInt32(Configuration["Port"]),
            SenderName = Configuration["SenderName"],
            SenderEmail = Configuration["SenderEmail"],
            Account = Configuration["SenderEmail"],
            Password = Configuration["SenderPassword"],
            Security = true
        });
    });

下面是EmailService的代码：

    public void Send(string mailTo, string subject, string message, bool isHtml = false)
    {
        SendEmail(mailTo, null, null, subject, message, Encoding.UTF8, isHtml);
    }

    private void SendEmail(string mailTo, string mailCc, string mailBcc, string subject, string message, Encoding encoding, bool isHtml)
    {
        var _to = new string[0];
        var _cc = new string[0];
        var _bcc = new string[0];
        if (!string.IsNullOrEmpty(mailTo))
            _to = mailTo.Split(',').Select(x => x.Trim()).ToArray();
        if (!string.IsNullOrEmpty(mailCc))
            _cc = mailCc.Split(',').Select(x => x.Trim()).ToArray();
        if (!string.IsNullOrEmpty(mailBcc))
            _bcc = mailBcc.Split(',').Select(x => x.Trim()).ToArray();

        Check.Argument.IsNotEmpty(_to, nameof(mailTo));
        Check.Argument.IsNotEmpty(message, nameof(message));

        var mimeMessage = new MimeMessage();

        //add mail from
        mimeMessage.From.Add(new MailboxAddress(_MailKitProvider.Options.SenderName, _MailKitProvider.Options.SenderEmail));

        //add mail to 
        foreach (var to in _to)
        {
            mimeMessage.To.Add(MailboxAddress.Parse(to));
        }

        //add mail cc
        foreach (var cc in _cc)
        {
            mimeMessage.Cc.Add(MailboxAddress.Parse(cc));
        }

        //add mail bcc 
        foreach (var bcc in _bcc)
        {
            mimeMessage.Bcc.Add(MailboxAddress.Parse(bcc));
        }

        //add subject
        mimeMessage.Subject = subject;

        //add email body
        TextPart body = null;

        if (isHtml)
        {

            body = new TextPart(TextFormat.Html);
        }
        else
        {
            body = new TextPart(TextFormat.Text);
        }
        //set email encoding
        body.SetText(encoding, message);

        //set email body
        mimeMessage.Body = body;

        using (var client = _MailKitProvider.SmtpClient)
        {
            client.Send(mimeMessage);
        }
    }

如您所见，我已经完成了所有设置，我在这里缺少什么吗？为什么MimeKit.MailboxAddress()的地址为空？

Answer 1

您似乎没有正确加载配置设置。我怀疑您代码中的失败行是

//add mail from
mimeMessage.From.Add(new MailboxAddress(_MailKitProvider.Options.SenderName, _MailKitProvider.Options.SenderEmail));

选项全部为空，从而导致异常。

当从配置文件中加载设置时，您需要在节名称前添加变量。 E.G。

services.AddMailKit(optionBuilder =>
{
    optionBuilder.UseMailKit(new MailKitOptions()
    {
        //get options from sercets.json
        Server = Configuration["EmailConfiguration:Server"],
        Port = Convert.ToInt32(Configuration["EmailConfiguration:Port"]),
        SenderName = Configuration["EmailConfiguration:SenderName"],
        SenderEmail = Configuration["EmailConfiguration:SenderEmail"],
        Account = Configuration["EmailConfiguration:SenderEmail"],
        Password = Configuration["EmailConfiguration:SenderPassword"],
        Security = true
    });
});

Answer 2

我的猜测是，以下行引发了异常：

mimeMessage.From.Add(new MailboxAddress(_MailKitProvider.Options.SenderName, _MailKitProvider.Options.SenderEmail));

这意味着_MailKitProvider.Options.SenderEmail是null。

我知道您希望这些值可以从appsettings.json文件中正确加载，但表面看来，由于某些原因它们没有被加载。