Note that in this case, you probably want to supply a (blank) default value to fetch so that it doesn't raise a `KeyError` if `:email` isn't present.

```ruby
if invitation_params.fetch(:email, nil).blank?
else
end
```

I will say, it feels slightly weird to have this sort of code in the controller. I'd almost prefer a more generic error message, like "We weren't able to send your invitation. Be sure you've supplied an email address, and try again" and eschew validation-y stuff in the controller. Or maybe try pushing this logic into the model? Nothing feels great.

Also, looks like your spacing on the line below is slightly off.