I am trying to use adaptive cards within outlook I've got so far but then I ran into issue.
I can send adaptive cards to a users mailbox and this appears within outlook fine and I can click 'submit' button on the card and I get response back in power automate flow.
However when I try and do this and send to a shared Mailbox I get the error 'Failed to validate the signature of the actionable message card.'.
I followed this blog and initially worked for sending cards to users into my organization but not for Shared Mailboxes. The card does appear inside the shared mailbox I just get an error when clicking the button
https://powerplatformpuzzles.wordpress.com/2023/08/27/outlook-actionable-messages-not-working-blank/
Anything I may be doing wrong?