Develop Reference

C# SMTP MailMessage receiving error "5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM"

The code I currently have is:
public void SendEmail(string to, string cc, string bcc, string subject, string body, string attachmentPath = "", System.Net.Mail.MailPriority emailPriority = MailPriority.Normal, BodyType bodyType = BodyType.HTML)
{
try
{
var client = new System.Net.Mail.SmtpClient();
{
client.Host = "smtp-mail.outlook.com";
client.Port = 587;
client.UseDefaultCredentials = false;
client.EnableSsl = true;
client.DeliveryMethod = System.Net.Mail.SmtpDeliveryMethod.Network;
client.Credentials = new NetworkCredential("[my company email]", "[my password]");
client.Timeout = 600000;
}
MailMessage mail = new MailMessage("[insert my email here]", to);
mail.Subject = subject;
mail.Body = body;
client.Send(mail);
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
The email address I'm trying to send to is hosted on Office 365's Outlook. We might have to change the specific address later, but they'd likely be configured the same.
However, whenever I try to run the client.Send(mail); command, I receive the same error. The full text of the error is:
The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.57 SMTP; Client was not authenticated to send anonymous mail during MAIL FROM
I've tried a few different things, like switching the port between 25 and 587, changing the host to Office365's, or toggling UseDefaultCredentials and EnableSssl to true or false. But I always see the same error. Is there something else I'm missing?

I found an example code block elsewhere on this site and replacing everything I had with it made the difference.
The function name and parameters were the same, but here's what I replaced the body of it with.
var _mailServer = new SmtpClient();
_mailServer.UseDefaultCredentials = false;
_mailServer.Credentials = new NetworkCredential("my email", "my password");
_mailServer.Host = "smtp.office365.com";
_mailServer.TargetName = "STARTTLS/smtp.office365.com";
_mailServer.Port = 587;
_mailServer.EnableSsl = true;
var eml = new MailMessage();
eml.Sender = new MailAddress("my email");
eml.From = eml.Sender;
eml.To.Add(new MailAddress(to));
eml.Subject = subject;
eml.IsBodyHtml = (bodyType == BodyType.HTML);
eml.Body = body;
_mailServer.Send(eml);
I don't know for certain but I think that replacing the Host value with the smtp Office 365 link rather than an outlook one, as well as remembering to add a Target Name which I did not have before, both did the trick and solved the authorization issue (I had previously confirmed it wasn't a credentials issue with our tech support).

C# How to set 'return-path' for smtp mail

I am trying to set the 'return-path' for my emails but I'm not seeing it as an available parameter. It seems like replytolist is not the same thing. I wan't to set the location that bounced emails are delivered. Here is my code so far:
private static void SendMail(string html,string taxId,string toEmail,string filePath,string fromEmail,string replyToEmail,string emailSubject,string emailAttachPath)
{
try
{
MailMessage mail = new MailMessage();
mail.From = new MailAddress(fromEmail);
mail.To.Add(toEmail);
mail.Subject = emailSubject;
mail.Body = html;
//specify the priority of the mail message
mail.ReplyToList.Add(replyToEmail);
SmtpClient SmtpServer = new SmtpClient("smtp.server.com");
SmtpServer.Port = 25;
SmtpServer.UseDefaultCredentials = true;
SmtpServer.EnableSsl = false;
mail.IsBodyHtml = true;
SmtpServer.Send(mail);
}
catch (Exception ex)
{
Console.WriteLine(ex.ToString());
}
}

If you dont write return path emailaddress. Server will take from email address convert into the return path. You also can see email report in your email original source.
If you want to add custom reutn path you can use
MailMessage message = new MailMessage();
message.Headers.Add("Return-Path", "response#*****.biz");
Also if you using postfix and you want add return path Automatically You will have to make changes in two files
canonical :- put your return path emailaddress here.
//reply#domain.com
main.cf :- write your code in main.cf file
canonical_classes = envelope_sender
sender_canonical_maps = regexp:/etc/postfix/canonical

Asp.Net Email Attachment Displaying Inline on Mobile (iPhone)

I have an .Net 4.5 application that sends an email, with an attachment. It works as expected when the email is opened on a desktop, but when opened on a mobile (iPhone in this case) the attachment shows as inline HTML not as an attachment.
When however I forward the same email from my desktop to the phone, the attachment shows up correctly on my phone so I am almost certain that it has to do with how I am specifying mime or content-type, disposition etc. but I can't see what I am doing wrong.
Here is the code - note that
att.ContentType = new System.Net.Mime.ContentType("multipart/mixed");
does create an attachment on iPhone but it is of type = mime-attachment that will not open.
I'm stumped & client awaits - any help greatly appreciated !
private void SendNotice(string body, string attachment, string email, bool pdf = false)
{
MailMessage message = new MailMessage();
message.From = new MailAddress(ConfigurationManager.AppSettings["SMTP.SendFrom"]);
message.Subject = ConfigurationManager.AppSettings["MatchedNoticeSubject"];
message.To.Add(new MailAddress(email));
message.ReplyToList.Add(new MailAddress(ConfigurationManager.AppSettings["SMTP.ReplyTo"]));
message.Body = body;
message.IsBodyHtml = true;
Attachment att = Attachment.CreateAttachmentFromString(attachment, "SeniorInfo.html", System.Text.Encoding.ASCII, "text/html");
//specifying this creates an attachment of type "mime-attachment" that does not open
//att.ContentType = new System.Net.Mime.ContentType("multipart/mixed");
message.Attachments.Add(att);
SmtpClient server = new SmtpClient()
{
EnableSsl = (ConfigurationManager.AppSettings["SMTP.EnableSSL"].ToLower() == "true"),
Host = ConfigurationManager.AppSettings["SMTP.Server"],
Port = Convert.ToInt16(ConfigurationManager.AppSettings["SMTP.Port"]),
Credentials = new System.Net.NetworkCredential(ConfigurationManager.AppSettings["SMTP.Account"], ConfigurationManager.AppSettings["SMTP.Password"])
};
server.Send(message);
}

Solved after some trial and error fiddling.
Counter-intuitively the attachment ContentDisposition object is READONLY which lead me to believe that I couldn't meddle in it however the read object is apparently a reference to the actual Attachment.ContentDisposition since setting values on the read instance does (apparently) correct the problem. Also used the Enum for MediaTypeNames (System.Net.Mime.MediaTypeNames.Text.Html) tho I don't think that was the issue.
Email send now looks like this :
private void SendMatchNotice(string body, string attachment, string email, bool pdf = false)
{
MailMessage message = new MailMessage();
message.From = new MailAddress(ConfigurationManager.AppSettings["SMTP.SendFrom"]);
message.Subject = ConfigurationManager.AppSettings["MatchedNoticeSubject"];
message.To.Add(new MailAddress(email));
message.ReplyToList.Add(new MailAddress(ConfigurationManager.AppSettings["SMTP.ReplyTo"]));
message.Body = body;
message.IsBodyHtml = true;
// Create the file attachment for this e-mail message.
Attachment att = Attachment.CreateAttachmentFromString(attachment, "SeniorInfo.html", System.Text.Encoding.ASCII, System.Net.Mime.MediaTypeNames.Text.Html);
System.Net.Mime.ContentDisposition disposition = att.ContentDisposition;
disposition.DispositionType = "attachment";
disposition.Inline = false;
disposition.FileName = "SeniorInfo.html";
disposition.CreationDate = DateTime.Now;
disposition.ModificationDate = DateTime.Now;
disposition.ReadDate = DateTime.Now;
message.Attachments.Add(att);
SmtpClient server = new SmtpClient()
{
EnableSsl = (ConfigurationManager.AppSettings["SMTP.EnableSSL"].ToLower() == "true"),
Host = ConfigurationManager.AppSettings["SMTP.Server"],
Port = Convert.ToInt16(ConfigurationManager.AppSettings["SMTP.Port"]),
Credentials = new System.Net.NetworkCredential(ConfigurationManager.AppSettings["SMTP.Account"], ConfigurationManager.AppSettings["SMTP.Password"])
};
server.Send(message);
}

insert a link in to a email send using c#

I develop a program to send emails automatically using c#, and I want to insert a link to a web site to that email. How can I do it?
public bool genarateEmail(String from, String to, String cc, String displayName,
String password, String subjet, String body)
{
bool EmailIsSent = false;
MailMessage m = new MailMessage();
SmtpClient sc = new SmtpClient();
try
{
m.From = new MailAddress(from, displayName);
m.To.Add(new MailAddress(to, displayName));
m.CC.Add(new MailAddress("xxx#gmail.com", "Display name CC"));
m.Subject = subjet;
m.IsBodyHtml = true;
m.Body = body;
sc.Host = "smtp.gmail.com";
sc.Port = 587;
sc.Credentials = new
System.Net.NetworkCredential(from, password);
sc.EnableSsl = true;
sc.Send(m);
EmailIsSent = true;
}
catch (Exception ex)
{
EmailIsSent = false;
}
return EmailIsSent;
}
I want to send a link through this email. How should I add it to email?

You should be able to just add the mark-up for the link in your body variable:
body = "blah blah <a href='http://www.example.com'>blah</a>";
You shouldn't have to do anything special since you're specifying your body contains HTML (m.IsBodyHtml = true).

String body = "Your message : <a href='http://www.example.com'></a>"
m.Body = body;

Within the body. This will require that the body be constructed as HTML so the that a or can be used to render your link. You can use something like StringTemplate to generate the html including your link.

For some dynamic links, the email service providers will not show your link into email body if the link not prepend http (security issues)
like localhost:xxxx/myPage
m.body = "<a href='http://" + Request.Url.Authority + "/myPage'>click here</a>"

opennetcf.net.mail attachment help

Thanks for looking at my question.
I am trying to figure out attachments for OpenNetCF.Net.Mail. Here is the code for my SendMail function:
public static void SendMessage(string subject,
string messageBody,
string fromAddress,
string toAddress,
string ccAddress)
{
MailMessage message = new MailMessage();
SmtpClient client = new SmtpClient();
MailAddress address = new MailAddress(fromAddress);
// Set the sender's address
message.From = address;
// Allow multiple "To" addresses to be separated by a semi-colon
if (toAddress.Trim().Length > 0)
{
foreach (string addr in toAddress.Split(';'))
{
message.To.Add(new MailAddress(addr));
}
}
// Allow multiple "Cc" addresses to be separated by a semi-colon
if (ccAddress.Trim().Length > 0)
{
foreach (string addr in ccAddress.Split(';'))
{
message.CC.Add(new MailAddress(addr));
}
}
// Set the subject and message body text
message.Subject = subject;
message.Body = messageBody;
// TODO: *** Modify for your SMTP server ***
// Set the SMTP server to be used to send the message
client.Host = "smtp.dscarwash.com";
string domain = "dscarwash.com";
client.Credentials = new SmtpCredential("mailuser", "dscarwash10", domain);
// Send the e-mail message
try
{
client.Send(message);
}
catch (Exception e)
{
string data = e.ToString();
}
}
It is supposed to be a matter of tweaking it in the following way to allow attachments:
Attachment myAttachment = new Attachment();
message.Attachments.Add(myAttachment);
The problem is that I cannot figure out how to get the attachment to add. The lines above should be it with something else in the middle where I actually tell it what file I would like to attach. Any help on this matter will be greatly appreciated.
Thanks again!

As per this MSDN documentation, you can specify the filename of the attachment as a parameter. Thus, you can give the fullpath as the string parameter.

They have AttachmentBase which can be used to construct a email attachment. However, we cannot add the instance of AttachmentBase to the attachments of email message.
I think the Attachment class should inherit from AttachmentBase. I think this maybe a defect.