I am using premailer, and on my local machine I get links like this in the mail notes:

```
file://localhost/assets/header_logo.png

```

instead of 

```
http://localhost:3000/assets/header_logo.png

```

How do I configure premailer so that the url is correct while in development?

I tried adding 

```
Premailer::Rails.config.merge!(base_url: "http://localhost:3000") 

```

to my development config file, but the server barfs saying there is no method Premailer::Rails.config.

I also did this:

```
config.action_mailer.default_url_options = {:host => 'localhost:3000'}

```

to no avail...