Fix typo in documentation

doc/create-tasks-by-email.markdown

@@ -2,12 +2,13 @@ Create tasks by email
 =====================
 
 You can create tasks directly by sending an email.
+This feature is available by using plugins.
 
 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)
+- [Mailgun](https://github.com/kanboard/plugin-mailgun)
+- [Sendgrid](https://github.com/kanboard/plugin-sendgrid)
+- [Postmark](https://github.com/kanboard/plugin-postmark)
 
 These services handle incoming emails without having to configure any SMTP server.
 
@@ -17,18 +18,18 @@ 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**
+1. You send an email to a specific address, for 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
+3. The SMTP provider call the Kanboard web hook with the email in JSON or multipart/form-data formats
+4. Kanboard parses 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 local part of the email address must use the plus separator, for example **kanboard+project123**
+- The string defined after the plus sign must match a project identifier, for 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)
 
@@ -38,7 +39,7 @@ Incoming emails can be written in text or HTML formats.
 Security and requirements
 -------------------------
 
-- The Kanboard webhook is protected by a random token
+- The Kanboard web hook 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 Kanboard project must have a unique identifier, for example **MYPROJECT**
+- The Kanboard user must be a member of the project