​Adding an HTML signature to Microsoft Outlook

• Open your signature file in a web browser (use Chrome for best results)

• Copy the contents – Select and copy the whole content of the page
  (Windows: Ctrl + A and Ctrl + C)  
  ​(Mac: CMD + A and CMD + C)
• Make a new signature in Outlook
  Open the Signatures dialog in Outlook 
  (Windows: File > Options > Mail > Signatures)
  (Mac: Outlook > Preferences > Signatures)

• Add a new signature or select the one you want to overwrite
  
  
• Paste the signature by clicking the “Paste” button
  (Windows: Ctrl + V)
  (Mac: CMD + V)

• Save the signature
  ​
• Select the newly created signature as your new standard signature. You can now use your newly created signature.