1. Open the Mail.app email client.
2. In the Menu bar go to Mail > Preferences > Signatures
3. Choose the Google Suite account and click on the "+" button
4. Name the signature and click in the blank field. Please make sure to uncheck the box "Always match my default message font".
Leave the Mail.app opened and start a new window in your browser.
5. Open CHROME and go to https://www.signaturesatori.com/app/user
(Please use Google Chrome, copy/paste in Safari doesn't work correctly for Mail.app.)
Fill or update information for your signature.
(Your administrator sets what information you can edit)
6. When you are finished, click on the button "Save and Preview".
7. In this modal window carefully select the whole signature and copy it with CMD+C
8. Go back to Mail.app > click the empty field and paste the copied signature with CMD+V.
Images are not shown due to a Mail.app bug. But don't worry, it should display just fine when it will be used in an email.
9. Select your new signatures from a dropdown of Choose Signature section.
10. Close the window with the settings.
Your signature is ready!
Did something go wrong? Make sure you didn't miss these important steps:
1. The signature must be added as a part of Google account.
2. Make sure to leave the box "Always match my default message font" unchecked.
3. Always use Chrome to open your User page.