This module limits webform submissions based on configurable rules. You can set limits globally or per webform, for example, restricting a specific email address to a certain number of submissions within a given timeframe.
Limits webform submissions with various rules, eg. for a single email address, only 5 submissions per hour.
Features
Choose global fields or per-webform to check against, and achieve submission limit like "this email can only submit 5 webforms per hour, or only this webform 5 times per month".
Post-Installation
Settings are in third party settings (globally and per-webform).