https://github.com/mozilla/discourse-auto-email-in
This plugin takes 4 settings:
auto_email_in_enabled-
auto_email_in_divider: Set the divider between a parent category slug and sub category slug -
auto_email_in_domain: Set the domain of the email-in addresses -
auto_email_in_append: Append new email-in addresses, rather than overwriting
So with the default settings, when enabled, all category email-in addresses will be set to:
<slug>@example.com or <parent_slug>+<child_slug>@example.com
So, with a category under /c/help/faq, this would be help+faq@example.com
If the auto_email_in_append setting is enabled, then emails will be appended as an alternative, rather than overwriting the existing value.
So if your /c/help/faq category already has an email-in value of wont-somebody-help-me-please@example.com, enabling the plugin will change that email-in value to wont-somebody-help-me-please@example.com|help+faq@example.com. This means a user can email wont-somebody-help-me-please@example.com or help+faq@example.com and the email will go the same category.