Signing a product XML file when sending by E-mail (QLM Pro 10.2.18074.2)

Hi,

I use QLM completely off-line, my customers are not no the internet and my database is locally on my computer, not any server.

My software product also has options, there are managed using "Product Properties"

To activate the software on a customer's PC, I send him an E-mail containing activation key, product key and product properties xml file (QlmProductProperties.xml), after receiving a computer ID from him.

In the QLM management console I can use Mail Send in the "Manage Keys" category. I created my own template and added %Properties% as discussed in  https://support.soraco.co/hc/en-us/articles/115000785306-How-to-use-Product-Properties. so that the QlmProductProperties.xml is automatically attached to the mail. Very handy, the customer has everything in one mail and I only have to push one button.

The problem that I have is that the QlmProductProperties.xml which is send with the E-mail is not digitally signed and is then rejected.

If I create this file manually with Manage Keys->Activate->Advanced->Generate Product Properties file, then I see that this file contains a signature section, and this one is accepted by the software.

Is there a way to get the product properties file attached using %Properties% to be signed as well?