I've created a small add-in for Outlook 2007 that removes the attachments and inserts a link to the removed files. Everything works, however when modifying a message with a digital certificate the user will be prompted with a warning that saving the message will remove the certificate (which it should be since it's been modified).
I want to suppress the dialog or remove the digital signature before saving the modified messages. Messages without the signatures save with no issues.
There is an office. Signature names space available but it doesn't appear to be applicable to outlook mail items.