The correct way to trigger send emails from a notion database

I have a database in notion with many draft emails in place.

Trigger event: Update database Item
Action: Filter (Pabbly): Properties Send? Checkbox equals to 1.
Action: Send email in gmail.

Details of what I am doing:
(Note that I am on the free plan (until I make sure this works for my purposes)
- I create an item in the Notion database. By default checkbox is unchecked. Sometimes i finish the message right away and just check the "send" checkbox. Other times, I leave it there for a couple of hours and then finish it and check the box afterwards.
- I return the next day to see if the email was sent and it is wasn't. In fact, sometimes it works and sometimes it doesn't.

But I can't figure out how to make it work consistently.

Ideally, i would like the email to be send everytime I check the box, both if the item was just created or if it was an item created a few days ago and checked to be send today.

Thanks for your help

Hi @Danilo81,

Notion has a trigger interval of 24 hours, so it may take up to 24 hours for your workflow to be triggered when an item is updated.

This trigger interval can be reduced to 10 minutes for paid plans. If you wish, you can purchase any of our plans to reduce the trigger interval.
https://www.pabbly.com/connect/