System.Web.Mail.MailMessage attachment problem

[Trond A. S. Andersen]

Hi, all!

I'm trying to use the System.Web.Mail. "package" combinded
with System.Web.Mail.SmtpMail in order to send MS Excel
spreadsheets attached to mail messages. However, sending
one single spreadsheet attachment per message, seems to be
causing som kind of corruption of the attachment, while
several spreadsheets per works just fine. Consider the
following three snippets of C# code:

// Sample 1 ->

System.Web.Mail.MailMessage msg = new
System.Web.Mail.MailMessage();
msg.Attachments.Add(new System.Web.Mail.MailAttachment
("some_spreadsheet.xls"));
msg.Attachments.Add(new System.Web.Mail.MailAttachment
("some_other_spreadsheet.xls"));

msg.From = "(e-mail address removed);
msg.To = "(e-mail address removed)";
msg.Subject = "TWO Excel spreadsheets attached;

System.Web.Mail.SmtpMail.SmtpServer = "some_smtp_server";
System.Web.Mail.SmtpMail.Send(msg);


// Sample 2 ->

System.Web.Mail.MailMessage msg = new
System.Web.Mail.MailMessage();
msg.Attachments.Add(new System.Web.Mail.MailAttachment
("some_spreadsheet.xls"));

msg.From = "(e-mail address removed);
msg.To = "(e-mail address removed)";
msg.Subject = "TWO Excel spreadsheets attached;

System.Web.Mail.SmtpMail.SmtpServer = "some_smtp_server";
System.Web.Mail.SmtpMail.Send(msg);

// Sample 3 ->

System.Web.Mail.MailMessage msg = new
System.Web.Mail.MailMessage();
msg.Attachments.Add(new System.Web.Mail.MailAttachment
("some_other_spreadsheet.xls"));

msg.From = "(e-mail address removed);
msg.To = "(e-mail address removed)";
msg.Subject = "TWO Excel spreadsheets attached;

System.Web.Mail.SmtpMail.SmtpServer = "some_smtp_server";
System.Web.Mail.SmtpMail.Send(msg);


Using the code in Sample 1, both attatchments can be
opened by Excel without any problem, as they arrive at the
receiving end.

Using the code in Sample 2 or Sample 3, however, NEITHER
of the attachments, which happens to be the EXACT same two
Excel spreadsheets as in Sample1, can be opened by the
receipient using Excel. Any ettemt two open them results
in either a "The document is corrupt and cannot be opened.
To try an repair..." error message or a " cannot
be accessed. The file may be read-only, or..." error
message. If any of you have an idea what's causing this
problem, and maybe even a suggestion for a workaround,
your reply would be highly appreciated.

Regards, Trond

 

[Val Savvateev]

Try to use encoding parameter in MailAttachment constructor.

 

[Trond A. S. Andersen]

Tried that. Excel spreadsheet attachments somehow
corrupted by the System.Web.Mail/System.Web.Mail.SmtpMail
framework, no matter what encoding parameter i use.

Thanks, anyway