How to update default email signature?

Email signature setting is found under Accounts setting, and you can update it by going to Accounts from top right round menu.

This is how you can find the email signature setting:

Note: This email signature is dependent on the Aritic PinPoint owner’s account and when used inside the email template asset and email campaign as {signature} token then this token is resolved from the Aritic PinPoint owner’s account. This Aritic PinPoint owner’s account is fetched from the email template asset and email campaign settings.

Also, {signature} is completely independent of “From Name” and “From Email” tag used inside email template asset and email campaign settings.