Email templates : Is there possible to add the account name on an email template about a task ?

Hi.

I want to send a reminder by email to users when a task is scheduled today. The task is linked with a project or an opportunity. I want to add in my email template the name of the account linked to the project or the opportunity.
I used $account_name, but it didn’t work.

How can I do that ?

Thanks for your help.