To expand on what TheycallmeXiaoli said :
Create a new mail in apple "Mail.app", write Bonjour
then hit cmd + s.
Find your draft at the left panel of "Mail.app". Drag it onto your desktop.
Edit the draft file with any text editor you like (ex: TextEdit)
Search for the word Bonjour
you wrote earlier - Replace ONLY this Bonjour
with your ENTIRE html code
then save the file.
do not delete anything else ! don't replace the current HTML tag just the word Bonjour
- In the Mail App Select File -> Import Mail Boxes
Select "Apple Mail" & import the edited file.
- You will see your mail at the left panel of Mail App
most likely inside an "imported" folder
- Drag the file into your "Draft" mailbox.
Finally open the mail, fill in To, CC, Subject, etc, and send your pure HTML mail.
: )
Thanks so much TheycallmeXiaoli !