SecureBlackbox 16: Signed messages with attachments in Microsoft Exchange

Note: This article applies only to SecureBlackbox Legacy. For future development please consider using the latest version.

If you are getting the following error, you may have encountered a known bug in Microsoft Exchange: a signed message with an attachment is reported as containing an invalid signature when processed by Microsoft Exchange.

Microsoft Exchange 2007 contains a bug that causes it to invalidate the signatures made over documents containing file attachments.

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