You don’t say much about how the rule is set up, and that has a bearing on the results that you get. But from what you write, it appears that there’s a daily rule that matches certain criteria, and then that happens, it sends a notification.
Trouble is, if the criteria do not change, then every day the same notification will be sent.
There are various ways to avoid this issue, and some of them make more sense depending again on what exactly you’re tracking as criteria, and what you wish to accomplish.
One way may be to evaluate a date field, and run the rule based on a specific date.
E.g: Send the notification if “today” is Expiration Date + 3 Days, or Send the notification if the Renewal Date is 5 days old. These are specific dates, so it will trigger only once provided the rule runs every day.
In some other cases you may need to have a flag field that you use to validate with an if-then-else rule:
a. If something happens (maybe click a button), set flag to “Yes”
b. Your daily rule finds any records where the flag is “yes”
b1. Rule sends notification
b2. Rule sets the flag to “no”.
Again, unless the same thing happens that sets the flag to “yes” again (in some cases that’s exactly what you want), this would only trigger once, because the same notification rule sets the flag to “no”, so the record doesn’t qualify anymore.
These are two of the most common ways you can use to ensure that a time-based rule only runs once on any given record. If this doesn’t work for you, then please give more details about what you’re tracking, to give you some other suggestions.