Hi @Anonymous, @edgonzales got there before me with the same solution using 5 and 0 but I'll post the screenshots of the flow example anyway in case they help. There is a SharePoint list called CropSurveyIncrement which will only ever have 1 item:
Separate SharePoint list holding the current value
Trigger, get the response details, get the value from the increment list
Add a condition
if the value ends with 5 or 0 send email, update the number
Rob
Los Gallardos
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