Last Updated: 03-10-2018
Open your web browser and go to https://portal.office.com. Sign in with your Office 365 username and password.
Click on the Cog Wheel in the top right hand corner to access your Settings.
Click on Mail under Your App Settings
Select Email signature under Mail > Layout in Options
Create your signature in the box. Select any of the options about automatically including your signature as required. When you are happy with your signature click Save
Now test sending some e-mails to check your signature looks as it should
If you want to create a signature with a relatively complex layout including pictures then you will be best to create a table to hold the different parts of the signature and allow you to format them independently of each other.
If you want to stop the gridlines of a table from showing, right click within the table to access more options. Then select Style > Clear