Help with Custom Mail Header

Hi -

I'm stuck on something 'simple' - custom mail header. Seems this
should work but can't get it to come out correctly. Any help
appreciated:

http://pastie.org/private/skedkstanvm8hpzr8ounia

In your call to #mail:

    mail(:to => 'test@sample.com',
         :from => email,
         :subject => "Message from the site",
         :headers['X-SMTPAPI'] => "{\"category\" : \"Drip Email\"}"
    )

you're passing a hash of headers to the #mail method, and one of your keys is :headers['X-SMTPAPI']. Ruby tries to execute this as calling the #[] method on the symbol :headers, which returns nil (under ActiveSupport).

This all happens before the #mail method gets a chance to see it; in other words, your method call looks like this:

    mail(:to => 'test@sample.com',
         :from => email,
         :subject => "Message from the site",
         nil => "{\"category\" : \"Drip Email\"}"
    )

That's why you're seeing the {"category" : "Drip Email"} value appear in your email, but with an empty name for the header.

To set a header value, you can either specify it directly in the hash you pass to #mail:

    mail(:to => 'test@sample.com',
         :from => email,
         :subject => "Message from the site",
         'X-SMTPAPI' => "{\"category\" : \"Drip Email\"}"
    )

or you can use the #headers method separately:

    headers['X-SMTPAPI'] = "{\"category\" : \"Drip Email\"}"
    mail(:to => 'test@sample.com',
         :from => email,
         :subject => "Message from the site"
    )

Chris