Are email signatures visible when composing emails?
Yes, signatures are inserted directly below the email when composing email in Outlook for Windows, Outlook for Mac and Outlook on the Web. This works by running the Email Signature Manager Agent on users' machines. See the user's guide for more information.
When sending email from other email clients, signatures are added after email is sent and therefore not visible when composing email. Support for other email clients requires enabling the Signature Injection Service for Office 365 or installing the Email Signature Manager Transport Agent on Exchange Server. See the user's guide for more information.