In an Office 365 environment there are different ways to setup and manage email signatures for all employees.
Making email signatures visible is often requested - Here's a quick overview:
|Outlook on Windows||Yes||Xink client|
|Outlook on Windows||Yes||Xink client (centrally deployed)|
|Outlook on Mac||Yes||Xink client |
|Mail on Mac||Yes||Xink client|
|Outlook on the web (browser)||Yes||Integration with Office 365|