尝试从 ASP.NET 页面通过 SMTP 发送 email 时出现权限问题

Question

I have done this before without any issue but now I don't know what's wrong. I have a web page with a button for email which I want to send some data to email addresses with.

I asked our web hosting company for server details and the response I got was:

"You can use the following details for mail.

Incoming mail server: mail.ourSite.com Outgoing mail server: mail.ourSite.com

Username and password are the email address and password associated with the email address.
"

I am not sure about the last line but I created a new email address in the web host's control panel.

The code I use is:

// instantiate a new mail definition and load an html
// template into a string which I replace values in
// then the rest of the code below
md.Subject = String.Format("{0} {1} {2}", emailSubject, firstName, lastName);

MailMessage msg = md.CreateMailMessage(emailAddress, replacements, emailBody, new Control());
md.IsBodyHtml = true;
SmtpClient sc = new SmtpClient(emailServer);            
sc.Credentials = new NetworkCredential(emailUsername, emailPassword);
    try
    {
        sc.Send(msg);
    }

emailServer - mail.ourSite.com (dummy value in this post) emailUsername - the email address I created in the control panel emailPassword - the password for the email above

The error I have is that when I send emails to other domains than our own I get

"Bad sequence of commands. The server response was: This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server."

When I email to an address within our host then it works fine.

The support is not very supportive so I am asking here what you might think the problem could be? I find it strange that I use the password for an email address I created, should it really be like that?

Answer 1

I think that you are using the wrong email address for the NetworkCredential . It should be the one for your email account that you got from the one providing emailServer .

Answer 2

Try this..

    msg.UseDefaultCredentials = false;
    NetworkCredential MyCredential = new NetworkCredential("Email", "Password");
    msg.Credentials = MyCredential;

Answer 3

here is code to send mail.. i hope i will helpful to you..

using System.Web.Mail;
using System;
public class MailSender
{
    public static bool SendEmail(
        string pGmailEmail, 
        string pGmailPassword, 
        string pTo, 
        string pSubject,
        string pBody, 
        System.Web.Mail.MailFormat pFormat,
        string pAttachmentPath)
    {
    try
    {
        System.Web.Mail.MailMessage myMail = new System.Web.Mail.MailMessage();
        myMail.Fields.Add
            ("http://schemas.microsoft.com/cdo/configuration/smtpserver",
                          "smtp.gmail.com");
        myMail.Fields.Add
            ("http://schemas.microsoft.com/cdo/configuration/smtpserverport",
                          "465");
        myMail.Fields.Add
            ("http://schemas.microsoft.com/cdo/configuration/sendusing",
                          "2");
        //sendusing: cdoSendUsingPort, value 2, for sending the message using 
        //the network.

        //smtpauthenticate: Specifies the mechanism used when authenticating 
        //to an SMTP 
        //service over the network. Possible values are:
        //- cdoAnonymous, value 0. Do not authenticate.
        //- cdoBasic, value 1. Use basic clear-text authentication. 
        //When using this option you have to provide the user name and password 
        //through the sendusername and sendpassword fields.
        //- cdoNTLM, value 2. The current process security context is used to 
        // authenticate with the service.
        myMail.Fields.Add
        ("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate","1");
        //Use 0 for anonymous
        myMail.Fields.Add
        ("http://schemas.microsoft.com/cdo/configuration/sendusername",
            pGmailEmail);
        myMail.Fields.Add
        ("http://schemas.microsoft.com/cdo/configuration/sendpassword",
             pGmailPassword);
        myMail.Fields.Add
        ("http://schemas.microsoft.com/cdo/configuration/smtpusessl",
             "true");
        myMail.From = pGmailEmail;
        myMail.To = pTo;
        myMail.Subject = pSubject;
        myMail.BodyFormat = pFormat;
        myMail.Body = pBody;
        if (pAttachmentPath.Trim() != "")
        {
            MailAttachment MyAttachment = 
                    new MailAttachment(pAttachmentPath);
            myMail.Attachments.Add(MyAttachment);
            myMail.Priority = System.Web.Mail.MailPriority.High;
        }

        System.Web.Mail.SmtpMail.SmtpServer = "smtp.gmail.com:465";
        System.Web.Mail.SmtpMail.Send(myMail);
        return true;
    }
    catch (Exception ex)
    {
        throw;
    }
}
}