Hi!
I know it’s been three months since you asked, but I’ll answer anyway.
If you put *|MC:SUBJECT|* you should have the title of you post displayed.
You can either put it in the mail title or inside the mail body.
On my side, I’m having issues usind ‘main’. I can’t get it to work although I did everything that was told in the help section of MailChimp.
Could you help with showing how you use it in your template, please?