# Discourse Developer Testing Guide Some notes about testing Discourse: ## MailHog Discourse depends heavily on (sending) email for notifications. We use [MailHog](https://github.com/mailhog/MailHog) to test emails. It's super convenient! > MailHog runs a super simple SMTP server which catches any message sent to it to display in a web interface. Run mailhog, set your favourite app to deliver to smtp://127.0.0.1:1025 instead of your default SMTP server, then check out http://127.0.0.1:8025 to see the mail that's arrived so far.