Ruby On Rails: ActionMailer : Get full URL to an image in a Rails asynchronous mailer

Well this is odd behavior, but I’ve resolved this issue. It turns out that unless the action_mailer.asset_host starts with http:// then it will be ignored. There is a Regex in actionpack/lib/action_view/helpers/asset_url_helper.rb that defines a valid ActionMailer URI:

URI_REGEXP = %r{^[-a-z]+://|^(?:cid|data):|^//}

However, Continue reading