How to use helper methods in mailer templates

How to use helper methods in mailer templates? Instead of this "include YourHelper" use this "add_template_helper YourHelper" in YourMailer

How to add images (i.e. logo) to email messages while using Pony gem.

Pony gem allows to easily send good looking and customizable emails, but it doesn't provide a way to include image in a way that it will be displayed in gma...

How to include logo into devise messages

A quick guide how to include any file, in this case logo to devise messages