While we do not have a feature for email templates or canned responses you can always create a work item, send yourself emails with the canned responses and from your Triage add these to your timeline for this work item. You can then reference this work item at anytime and copy and paste these into your emails as required.
To create canned messages to use for common responses, create a work item called "Email Templates" or similar. It's a good idea with a start date and due date far into the future, so that it doesn't pops into your work view or in your to-do list.
Once this work is created, you can send yourself emails using the subject line as the type of email template and then tag it to the work item you created. You will be able to copy from these “templates” and paste them into new emails.