ISH - How to Make an HTML Signature in Apple Mail for Yosemite OS X 10.10
1. In Apple Mail, go to Preferences > Signatures and create a signature with any random content. Name it something meaningful. You will be swapping this out later.
2. Associate the placeholder signature with one of your email accounts by dragging it’s name from the second column in the Preferences > Signatures window to an email account in the first column.
3. Close the Preferences window to save it, then quit Apple Mail.
4. We are going to need to locate the folder containing the placeholder signature. Unfortunately, you are not going to be able to use Finder to get to these folders.
Apple goes to great lengths to hide these files from people as they usually contain info that is not editable by hand. Trying to navigate through by clicking in Finder will usually lead you to your visible iCloud Drive folder with nowhere to go. Don’t worry though, I will walk you through an alternative method of getting at those files.
The files can be in 3 different places depending on whether you are using iCloud Drive, iCloud without Drive, or no iCloud at all. If you know which one you are, great! If you don’t, start with the top one and work your way down if you can’t find the folder. You will find the lines below the Screenshot.
Click with two fingers on the Finder icon and choose "Go to Folder"
a) Using iCloud Drive:
b) Not using iCloud Drive, but still using iCloud:
c) Not using iCloud:
You should see the following folder:
Click with two finger on the .mailsignature file and choose open with - other and choose TextEdit
Replace everything except the top part which isn´t highlighted.
Replace the highlighted part with the html coding that you find in this document:
and for the rest of Helsingborg:
Make sure to change the highlighted sections in the document to your details. You don´t want my signature underneath your email!
5. Open Apple Mail and go back to Preferences > Signatures. If you have images in your signature, they will will not show here in the preview, but they will show in the real signature if the image source location is valid.
6. To test that it is working correctly, simply compose a new email using the account you associated this signature with in step 2, and set the signature (right side of screen) to be the one with the name you created in step 1. If the images show, and everything looks as it should, you have succeeded!