Add Mailgun integration (incoming emails)

docs/mailgun.markdown

@@ -0,0 +1,61 @@
+Mailgun
+=======
+
+You can use the service [Mailgun](http://www.mailgun.com/) to create tasks directly by email.
+
+This integration works with the inbound email service of Mailgun (routes).
+Kanboard use a webhook to handle incoming emails.
+
+Incoming emails workflow
+------------------------
+
+1. You send an email to a specific address, by example **something+myproject@inbound.mydomain.tld**
+2. Your email is forwarded to Mailgun SMTP servers
+3. Mailgun call the Kanboard webhook with the email in JSON format
+4. Kanboard parse the received email and create the task to the right project
+
+Note: New tasks are automatically created in the first column.
+
+Email format
+------------
+
+- The local part of the email address must use the plus separator, by example **kanboard+project123**
+- The string defined after the plus sign must match a project identifier, by example **project123** is the identifier of the project **Project 123**
+- The email subject becomes the task title
+- The email body becomes the task description (Markdown format)
+
+Incoming emails can be written in text or HTML formats.
+**Kanboard is able to convert simple HTML emails to Markdown**.
+
+Security and requirements
+-------------------------
+
+- The Kanboard webhook is protected by a random token
+- The sender email address must match a Kanboard user
+- The Kanboard project must have a unique identifier, by example **MYPROJECT**
+- The Kanboard user must be member of the project
+
+Mailgun configuration
+---------------------
+
+Create a new route in the web interface or via the API ([official documentation](https://documentation.mailgun.com/user_manual.html#routes)), here an example:
+
+```
+match_recipient("^kanboard\+(.*)@mydomain.tld$")
+forward("https://mykanboard/?controller=webhook&action=mailgun&token=mytoken")
+```
+
+The Kanboard webhook url is displayed in **Settings > Integrations > Mailgun**
+
+Kanboard configuration
+----------------------
+
+1. Be sure that your users have an email address in their profiles
+2. Assign a project identifier to the desired projects: **Project settings > Edit**
+3. Try to send an email to your project
+
+Troubleshootings
+----------------
+
+- Test if your route match in the console
+- Double-check requirements mentioned above

docs/postmark.markdown

@@ -21,7 +21,7 @@ Email format
 
 - The local part of the email address must use the plus separator, by example **kanboard+project123**
 - The string defined after the plus sign must match a project identifier, by example **project123** is the identifier of the project **Project 123**
-- The email subject becomes the task subject
+- The email subject becomes the task title
 - The email body becomes the task description (Markdown format)
 
 Incoming emails can be written in text or HTML formats.