If you are using Office 365 and have deployed the Signitic Add-in, you have the ability to set up signature delegations.
Delegation allows you to display a signature from a user other than the logged in user. It also allows you to have access to the signatures of your shared mailboxes on Outlook Windows.
To activate the delegation of a user, go to the user file of the person whose signature you wish to delegate (the shared mailbox for example) and then to the Delegation tab:
Then, just type the emails of the users who will have access to this signature and don't forget to save!
On the Add-in side, thanks to the delegation, the right signature will be displayed directly when you write from the shared mailbox.
You have a direct view of users who request access to other signatures from the Signitic dashboard. It's up to you to accept or not the request and the delegation will be done automatically.