```ruby
class ApplicationMailer < ActionMailer::Base

  default from: 'noreply@od-ot.herokuapp.com'

end
```

Add dafault url options to fix specs
user
```ruby
class ApplicationMailer < ActionMailer::Base

  default_url_options[:host] = 'localhost:3000'
  default from: 'noreply@od-ot.herokuapp.com'

end
```
assistant