Read Outlook attachment content in Outlook add-in (C# ) while creating a mail

Question

I am trying to develop an outlook add-in in VS 2010. It's purpose is to scan email body and attachment content for some key words and if any such words are found, email sending should be blocked. I am able to read email body and subject and to the validation but I am not understanding how to read an attachment content (txt file) while composing the mail.

attachment.GetTemporaryPath() is not giving the attachment path. I guess this works only for mails in inbox. One way I found was saving the attachment to a temp folder and reading it (attachment.saveAs()). Is this the only way to read attachment content while composing a mail ?

Possible Duplicate : C# Outlook 2007 - How do I access attachment contents directly from my addin?

But as suggested in there, I cant use Redemption. Is there any other way?

Answer 1

Yes, saving the attachment data to a temporary file and reading it s the only way. In theory, you can use Attachment.PropertyAccessor.GetProperty to read the PR_ATTACH_DATA_BIN property, but you will run into problems for the large (> 64kB) files.

You can also use Extended MAPI to open the attachment data as IStream (IAttach::OpenProperty(PR_ATTACH_DATA_BIN, IID_IStream)), but it is only accessible through C++ or Delphi. You can use Redemption (any language - I am its author) that wraps Extended MAPI and exposes AsArray and AsText properties on both RDOAttachment and the Attachment object exposed by the Safe*Item objects.