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How to add a Custom HTML email signature for Mac Mail


Luda Feitser

January 31, 2013 03:01PM


There are two ways to do this, it would vary depending if you have iCloud running on your system or not.


1. Create a signature placeholder in your Mail App by navigation to Mail --> Preferences --> Signatures tab

             A. Quit Mail



2. Write up your new signature using a text editor of some kind, I use TextMate.

          A. All the HTML has to be inline, including the CSS etc. Do not include any < body > or < head > tags.



3.  Click on the finder icon on the dock below and select “Go to Folder” and navigate to your signature folder found usually under ~/Library/Mail/MailData/Signatures

         A. Search for the signature you just created by inspecting the date modified or by viewing the signature in the preview.

         B. If your OS version still creates .webarchive then you will need to open up your newly created HTML signature in Safari and save as a “web-archive” under the Save As option.

                    I. Then copy the XXXXXXXXX.webarchive letter and number sequences of the placeholder signature you just created and rename the newly saved webarchive that you just saved.

                    II. Copy or drag the newly renamed webarchive into the folder under  ~/Library/Mail/MailData/Signatures to replace the file that was in there.

                    III. Relaunch Mail

         C. If you have a newer version of OS and your signatures save as .mailsignature then open the newly created placeholder signature with a text editor.

                  I. Right click, select “Open with” and if no default programs are offered, select “other” and open with the native Text Editor on your OS.

                  II. Leave the header information that is located at the top of the file. Only replace/remove the information enclosed within the < body > tags with your newly created HTML. You will paste this information and then save it.

2. Relaunch Mail and your new signature will now display where the place holder one existed before. Images that you may have added will not always display when you view the signature under Preferences but will show/display when you actually use the signature in emails.


1. If you have iCloud runnin on your OS, the only difference from the above instructions is that you will navigate by using "Go to Folder" to your iCloud signature folder to do the same steps of opening up with a text editor and replacing the < body > with your new HTML.

The reason for this is because iCloud will override any signature or signature changes you make via the ~/Library/Mail/MailData/Signatures area.

         A. You can access your iCloud signature by using "Go to Folder" and navigating to ~/Library/Mobile Documents/com~apple~mail/Data/MailData/Signatures/

         B. Find your placeholder signature and do the same steps and replace the

with your inline HTML. Save.

         C. Relaunch Mac Mail.


The Author

Luda Feitser