File Attachments MDAC Not Working Past 100K

[AspDotNetDeveloper]

I'm trying to troubleshoot why my ASP application can no longer send file
attachments larger than 100K, and I have eliminated many possibilities
already, but I'm running out of ideas.

I think I have it narrowed down to an Outlook Express update that is
installed on the Win 2K Server, but when I try to remove the update, then
the application returns an Unknown Error during the objNewMail.Send function
call.

The symptoms are empty file attachments, if the file that is trying to be
attached is larger than 100K. It still sends the email, and appears to send
the attachment too, but when the email is opened, the attachment is either
zero, or a few bytes. File attachments under 100K send fine.

Interestnig thing that leads me to beleive it is an Outlook Express update
causing the problem, is that when I uninstalled the update, even though the
application then returns an Unknown Error at some point during the
objNewMail.Send, the application sends the email, with a much larger portion
of the file attachment, although when trying to open the attachment, it
still is corrupt.

Anyone know of any fixes for this problem??? Or, has anyone else experienced
the same thing? The application used to work just fine, and no modifications
have been done to it, so I've ruled out a coding problem.

Thanks!

 

[AspDotNetDeveloper]

Yeah, I've checked and re-checked this, and I've even cranked it up and
tried that. It's really bizarre. Everything appears to be configured
correctly for sending email file attachments. This problem is happening on
both my test and production servers, and both servers have the Outlook
Express update from the Windows Update installed on them.

I know in other versions of Windows you can go into Add / Remove Windows
Components, and uninstall Outlook Express, but Win 2K Server does not seem
to offer that option. I just re-installed Internet Explorer 6 w/ SP1, so
I'm going to see if that helps at all, as it should of re-installed Outlook
Express.

Any more ideas would be appreciated, and I'll let you know if I get it
working... this is the 3rd day I'm spending on this, so I'm getting a little
frustrated.

Thanks!

 

[AspDotNetDeveloper]

I do use a smart host smtp server, but the problem exists when I use the
existing smtp server, and no smart host. The mail goes into the Queue
folder, then gets sent from there. I have had the mail folders open, and
watched the files get placed, as they are getting sent.

The email attachment is truncated before it gets to the Queue folder
(observed the file size).

Actually, in order to use the CDONTS object, you need Outlook Express
installed (see microsoft kb article
http://support.microsoft.com/default.aspx?scid=kb;en-us;327219 ), so I am
betting it has something to do with the OE updates that have been installed
over the last few months.

Nothing in the event logs... checked there already

I'll try sending an attachment from Outlook Express, using my SMTP server on
the same machine as the web server, and see what happens... good idea.

Thanks!

 

[AspDotNetDeveloper]

I tried using the local smtp server to send an email w/ attachment using
Outlook Express, and it seemed to send the email, and file attachment
correctly. I beleive the problem is originating in the cdonts.dll, and that
could have been updated in the OE Update.