Hello everybody!

I'm writing an add-on for Outlook 2007 in Delphi. The purpose of this
add-on is to add digital signature to the outgoing messages. I use
event OnItemSend.

At the moment i save IMessage to MIME by
IConverterSession.MAPIToMIMEStm. Next, That file signed by external
application and i try to load signed file to IMessage by
IConverterSession.MIMEToMAPI. But then Outlook sends loaded message,
and it become little modified.
For example:
Content-Type: text/plain;charset="us-ascii"
becomes:
Content-Type: text/plain;
charset="us-ascii"
Naturally, signature is no longer valid.

So, how can i add digital signature to outgoing messages? Should I add
a signature some other way or send signed MIME instead of the original
message?

Thank you.