Adding an attachment to a signature

Hey folks, I’ve unsuccessfully searched the Q&A trying to find this seemingly simple answer.  I’ve also spent over an hour trying to find the solution in eM Client.
Q:  How do I add a simple .pdf attachment to a signature?  The Texas Real Estate Commission is requiring a form to be added to all Real Estate Agent/Broker emails.  If this is not possible with the current version, you might want to consider adding it.  The National Association of Realtors is the largest association in the US. 
THANK YOU in advance for your time, consideration and reply.

Hi Jim,
unfortunately adding an attachment to a signature is currently not an implemented feature.
I’ll mark this thread as an ‘Idea’ here on the forums so our developers can consider adding it in future upgrades.