November 15, 2023
Create HTML Signatures for Apple Mail
Step by step instructions for creating an HTML signature for the Apple Mail application on macOS.
Create a Default Signature using the Apple Mail Application
If you don't already have a signature in Apple Mail, start by opening the mail application. Go to the menu, select "Mail" -> "Settings". Click on the "Signatures" tab and create a new signature under "All Signatures". When you are finished, drag the new signature to your desired email account on the left:
Use the Finder to Open the Mail Signatures Location
Right click on the Finder icon in the Dock and select "Go to Folder...":
Type the following path in the title bar: ~/Library/Mail/ and press "Enter":
Open the "V" folder with the highest number, this is the version number of the mail application. In my case this was "V10":
Then open the folder "MailData":
Then open the folder "Signatures":
You should now see the contents of the "Signatures" folder:
Create Your HTML Signature
You can use any number of online tools to generate an HTML email signature. You can find one here on HubSpot:
Edit the Signature File
Right click on the ".mailsignature" file you want to modify. Select "Open With" and open the file in TextEdit. You may have to do this a couple of times to find the file you want if you have multiple signatures. The file names are not very descriptive. You should see something like this (the header will be followed by the signature you created earlier):
From the HTML signature generator that you used to create your signature, copy the signature's HTML code following the instructions on the site. Then you will paste this code into the file you opened in the previous step, replacing the existing signature code. You will want to preserve the header info shown in the above screenshot. Your file should now look something like this:
Save the file and close the editor.
This next step is important: if not performed, Apple Mail will overwrite your changes.
In the Finder, right click on the signature file you just edited and select "Get Info". In the resulting window, find the "Locked" checkbox and make sure it is checked. You can then close the window:
View the Result
Go back to the mail application and navigate back to the "Signatures" tab in "Settings". Select the signature that you updated to HTML and you will see your changes. Please note that any linked images will not show up in the preview:
You can; however, create a new email with your signature to see the full results:
