The Aloaha PDF Signature API (sign_pdf_file) of object aloahapdf.edit can sign also PDF Attachments of eMails.
The procedure is pretty easy. Just pass the email as .eml to the function sign_pdf_file as if it is a PDF Document. Aloaha will analyse the mail, extract the attached PDF documents, digitally sign them and attach them back to the emai.
This is the ideal solution to build a IIS Sink Gateway to sign all PDF Documents of outgoing emails!
Please make sure to use a recent build of Aloaha!
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