Here are the default rules used to avoid sending too many triggered emails to customers:

Barilliance will not send more than one email in 7 days from the same triggered email rule. For example if you have one rule that sends cart abandonment emails after 1 hour from abandonment, and the user comes back after 2 days and changes the cart content, the user will not receive a second email. If however you have 2 rules, and the second rule is set to trigger emails after 2 days, the user will receive a second email after 2 days from the last time the cart was changed.

To limit the number of emails a customer receives from a triggered email rule use this option:

This option is most useful if you are sending a coupon in the second email.

Customers who purchased will not receive cart abandonment emails for a period of 4 days.

The system will not send more than 1 email to the same recipient within 1 hour. This allows segmenting the emails by setting multiple emails to the same time.
The first email that matches the segment of the user will be triggered and the rest of the emails will be blocked. To determine the order in which the emails are checked use the priority settings in the rules list.

Viewed products emails will not be triggered if the customer has purchased within the last 30 days or currently has items in the cart.

Cart abandonment emails will not be triggered if the customer has purchased in the last 4 days.
Cart Abandonment emails will not be triggered if the customer sent herself 'Email My Cart' email in the last 25 hours.

Emails will not be sent for products which were out of stock for less than 48 hours 

If after a single feed update more than 20% of the products come back into stock at once no back in-stock emails will be sent for those products

No back in-stock email will be sent if the visitor received any other email from Barilliance in the last 2 days
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