Add Sendgrid integration (incoming email handling)

docs/create-tasks-by-email.markdown

@@ -0,0 +1,44 @@
+Create tasks by email
+=====================
+
+You can create tasks directly by sending an email.
+
+At the moment, Kanboard is integrated with 3 external services:
+
+- [Mailgun](http://kanboard.net/documentation/mailgun)
+- [Sendgrid](http://kanboard.net/documentation/sendgrid)
+- [Postmark](http://kanboard.net/documentation/postmark)
+
+These services handle incoming emails without having to configure any SMTP server.
+
+When an email is received, Kanboard receive the message on a specific end-point.
+All complicated works are already handled by those services.
+
+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 the third-party SMTP servers
+3. The SMTP provider call the Kanboard webhook with the email in JSON or multipart/form-data formats
+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

docs/mailgun.markdown

@@ -6,34 +6,7 @@ You can use the service [Mailgun](http://www.mailgun.com/) to create tasks direc
 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
+The [incoming email workflow is described here](http://kanboard.net/documentation/email-tasks).
 
 Mailgun configuration
 ---------------------
@@ -53,9 +26,3 @@ 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

@@ -6,40 +6,15 @@ You can use the service [Postmark](https://postmarkapp.com/) to create tasks dir
 This integration works with the inbound email service of Postmark.
 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 Postmark SMTP servers
-3. Postmark 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 (From header) 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
+The [incoming email workflow is described here](http://kanboard.net/documentation/email-tasks).
 
 Postmark configuration
 ----------------------
 
-- Follow the [official documentation about inbound email processing](http://developer.postmarkapp.com/developer-process-configure.html)
-- The Kanboard webhook url is displayed in **Settings > Integrations > Postmark**
+Just follow the [official documentation about inbound email processing](http://developer.postmarkapp.com/developer-process-configure.html).
+Basically, you have to forward your own domain or subdomain to a specific Postmark email address.
+
+The Kanboard webhook url is displayed in **Settings > Integrations > Postmark**
 
 Kanboard configuration
 ----------------------
@@ -52,4 +27,3 @@ Troubleshootings
 ----------------
 
 - Test the webhook url from the Postmark console, you should have a status code `200 OK`
-- Double-check requirements mentioned above

docs/sendgrid.markdown

@@ -0,0 +1,24 @@
+Sendgrid
+========
+
+You can use the service [Sendgrid](https://sendgrid.com/) to create tasks directly by email.
+
+This integration works with the [Parse API of Sendgrid](https://sendgrid.com/docs/API_Reference/Webhooks/parse.html).
+Kanboard use a webhook to handle incoming emails.
+
+The [incoming email workflow is described here](http://kanboard.net/documentation/email-tasks).
+
+Sendgrid configuration
+----------------------
+
+1. Create a new domain or subdomain (by example **inbound.mydomain.tld**) with a MX record that point to **mx.sendgrid.net**
+2. Add your domain and the Kanboard webhook url to [the configuration page in Sendgrid](https://sendgrid.com/developer/reply)
+
+The Kanboard webhook url is displayed in **Settings > Integrations > Sendgrid**
+
+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