Rails 3 + action mailer - Cannot loop to send emails

A user can create an object, and he has followers that I want to alert when he creates this object.

controller:

if @project.save
  format.html { redirect_to(@project, :notice => 'Project was successfully created.') }
  format.xml  { render :xml => @project, :status => :created, :location => @project }
  # Send a notification to project owner's followers :
  UserMailer.new_project(@project).deliver
else
  ...

user_mailer.rb:

def new_project(project)
    @url  = "http://localhost:3000/"
    @project = project
    # For each of project owner's follower, send an email notification
    @followers = project.owner.followers.all
    @followers.each do |f|
        @u = User.find(f.follower)
        mail(   :to => @u.email,
            :from => '"Beatrix Kiddo" <beatrix@example.com>',
            :subject => "#{project.owner.name} created a new project")
    end
end

Testing with a user that has 2 followers:

User.find(1).followers.count = 2

Follower.follower is the id of the user who's following.

Only 1 email is sent to the 1st follower, and the 2nd doesn't receive anything - what's wrong?

[SOLVED] => the .deliver method simply doesn't support multiple messages. Thx DR

ActionMailer does not support sending multiple messages with one deliver call. You have to move the loop outside of the new_project method:

Instead of

UserMailer.new_project(@project).deliver

try this:

@followers = @project.owner.followers.all
@followers.each do |f|
    UserMailer.new_project(@project, f).deliver
end

The new_project method then could look like this:

def new_project(project, follower)
    @u = User.find(f.follower)
    mail(:to => @u.email,
         :from => '"Beatrix Kiddo" <beatrix@example.com>',
         :subject => "#{project.owner.name} created a new project")
end

You can also move the .deliver call into your new_project method. This works for me using Rails 3:

def new_project(project)
  # ...
  @followers.each do |f|
    # ...
    mail(:to => @u.email,
         :from => '"Beatrix Kiddo" <beatrix@example.com>',
         :subject => "#{project.owner.name} created a new project").deliver
  end
end

To send the mails, you would use

if @project.save
   # ...
   UserMailer.new_project(@project)
else
   # ...
end