Attach a file from MemoryStream to a MailMessage in C#

Zain Ali picture Zain Ali · Mar 17, 2011 · Viewed 174.4k times · Source

I am writing a program to attach a file to email. Currently I am saving file using FileStream into disk, and then I use

System.Net.Mail.MailMessage.Attachments.Add(
    new System.Net.Mail.Attachment("file name")); 

I do not want to store file in disk, I want to store file in memory and from memory stream pass this to Attachment.

Answer

Waqas Raja picture Waqas Raja · Mar 17, 2011

Here is the sample code.

System.IO.MemoryStream ms = new System.IO.MemoryStream();
System.IO.StreamWriter writer = new System.IO.StreamWriter(ms);
writer.Write("Hello its my sample file");
writer.Flush();
writer.Dispose();
ms.Position = 0;

System.Net.Mime.ContentType ct = new System.Net.Mime.ContentType(System.Net.Mime.MediaTypeNames.Text.Plain);
System.Net.Mail.Attachment attach = new System.Net.Mail.Attachment(ms, ct);
attach.ContentDisposition.FileName = "myFile.txt";

// I guess you know how to send email with an attachment
// after sending email
ms.Close();

Edit 1

You can specify other file types by System.Net.Mime.MimeTypeNames like System.Net.Mime.MediaTypeNames.Application.Pdf

Based on Mime Type you need to specify correct extension in FileName for instance "myFile.pdf"