HOTFIX: .NET 4.0 (System.Net.Mail) Unable to send emails with large attachments (more than 3MB)

 

We have an official release for the issue and if you are facing this problem then I would recommend you contacting PSS and refer to this blog

http://blogs.msdn.com/b/vikas/archive/2010/04/05/bug-net-4-0-system-net-mail-unable-to-send-emails-with-large-attachments-more-than-3mb.aspx

I am expected it to be released in a public KB in some time but for the time being you can request for the hotfix by contacting PSS

UPDATE - 7/21/2010

If you prefer not to contact PSS, you can download the hotfix by yourself from the following link.

http://connect.microsoft.com/VisualStudio/Downloads/DownloadDetails.aspx?DownloadID=30226