ActionMailer Difficulties

I'm using ActionMailer in test mode (so, in the config file I have

config.action_mailer.delivery_method = :test

) I have my mailer set up as such...

def confirm(message, sending_user, user)
    @subject = "You have a message from #{sending_user.login}"
    @body["message"] = message
  @body["user"] = user
  @body["sender"] = sending_user
    @recipients = user.email
    @from = "admin@queer.berkeley.edu"
    @sent_on = Time.now
  end

And my confirm page set up as follows

Dear <%= @user.name %>
<%= @sender.login %> has sent you the following message %>
<%= @message %>

Now, if I let @user be some user and @sending_user be some other user,
if I work from the console with

MessageSender.deliver_confirm("Message!", @sending_user, @user)

it works, and I see the message in the hash built by the test mode.
But if I use the following code

def send_message
  @user = (session[:looked_upon_user])
  @sending_user = User.find(session[:user_id])
  @message = (params[:message])
  MessageSender.deliver_confirm(@message, @sending_user, @user)
end

it doesn't, even though the send message page works, with the
following code

<h1> Message Sent! </h1>
<p>
  <%= @sending_user.login %> sent the message
</p>
<p>
  <%= @message %>
</p>
to <%= @user.login %>
<%= link_to "Return", :action => "index" %>

I've been programming with Ruby on Rails for a few months now and am
still trying to get the hang of it. Any help would be greatly
appreciated.