Create a new Placeholder Signature

• Open Apple Mail
• Select Preferences from the Mail menu
• In the Mail Preferences window, click the Signatures icon
• Select the account in the left panel you want to create a signature for
• Click the plus (+) icon near the bottom of the middle panel
• The name of the signature will be highlighted in the middle panel. Change this name to be something descriptive incase you have multiple signatures (Formal, Casual, No Images, etc)
• Replace the text in the right pane with something like __REPLACE_ME___. You will be replacing this text with your new signature in the next step
• Close the Preferences window and close Apple Mail

Replace the placeholder with your new HTML signature

• Open Finder and click on the Go menu
• Select Library from the dropdown menu. (note: if you do not see Library on the menu, hold down the Option key)
• If you are NOT using iCloud:
  • browse to ~/Library/Mail/V_/MailData/Signatures/ (where the _ in V_ will be a number)
• If you are using iCloud:
  • browse to ~/Library/Mobile Documents/com~apple~mail/Data/MailData/Signatures/
• This folder will contain a separate file for each signature in Apple Mail with a filename beginning with a string of letters and numbers. If you have file extensions visible, you'll also see they have a file extension of .mailsignature. The newest file will be the one you want to edit.
• Right click (or hold Control and click) the signature file and select Open With > Text Edit
• Open the signature generator
• Fill in your details to create the new email signature
• Click the green Select and Copy Code button
• Click OK in the confirmation dialog box
• Go back to Text Edit
• Select the text __REPLACE_ME__ in your open email signature and paste the new signature in place
• If you are NOT using iCloud:
  • Click the small down arrow ∨ next to the file name at the top of the text edit window to show the file options.
  • Tick the Locked Checkbox
• Close the signature file and quit Text Edit
• Now open Apple Mail and compose a new message to test your signature

Create a new Signature

• Open the signature generator
• Fill in your details to create the new email signature
• Click the green Select and Copy Formatted Signature button
• Click OK in the confirmation dialog box
• Open Gmail
• Select the Gear Icon and click settingsfrom the menu.
• Scroll down to the Images section
• Select Always display external images
• Scroll down the page to the Signature section
• Paste the signature into the signature box
• Scroll to the bottom of the page and click Save Changes
• Now compose a new message to test your signature

Create a new Signature

• Open Microsoft Outlook
• Select File from the top menu
• Click Options from the left menu
• Click the Mail category on the left panel
• Click the Signatures button on the right
• Click the New button in the signatures window
• Enter a descriptive name incase you have multiple signatures (Formal, Casual, No Images, etc)
• Click OK
• Open the signature generator
• Fill in your details to create the new email signature
• Click the green Select and Copy Formatted Signature button
• Click OK in the confirmation dialog box
• Go back to the Outlook Signature Editor
• Paste the signature into the signature box
• Click OK at the bottom of the signatures window
• Now compose a new message to test your signature