Unable to send email when view has links - ruby-on-rails

Question

I am using ruby 1.9.3p194 and Rails 3.2.3.
I am facing problem while sending emails whose template has a link in it. I have written following code:
invitation_mailer.rb
def event_invitation(user, event)
#user = user
#event = event
mail(:to => #user.email, :subject => "Invitation to participate in #{#event.name} event")
end
event_invitation.html.haml
Hello,
%br
%br
Your friend #{#event.user.full_name} has invited you to participate in #{#event.name} event. If you want to accept
this invitation, use the following link:
= link_to calendar_index_url, calendar_index_url
%br
%br
#{t('shared.team')}
user.rb
def xyz
...
InvitationMailer.event_invitation(self, event).deliver
end
If I remove the link line in the view, I am able to receive emails but not with the link inside the view. But the log shows that an email has been sent.
LOG
Sent mail to abhimanyu#gmail.com (6117ms)
Date: Fri, 02 Nov 2012 20:59:33 +0530
From: invitation#dev.tld
To: abhimanyu#gmail.com
Message-ID: <5093e6dd6a275_14f733fc536034cd444087#Abhimanyus-iMac.local.mail>
Subject: Invitation to participate in new event event
Mime-Version: 1.0
Content-Type: text/html;
charset=UTF-8
Content-Transfer-Encoding: 7bit
Hello,
<br>
<br>
Your friend Abhimanyu Kumar has invited you to participate in new event event. If you want to accept
this invitation, use the following link:
http://localhost:3000/calendar
<br>
<br>
Dev Team
Any help to figure out the problem would be appreciated.
Thanks in advance.

Answer 1

Did you specify the ActionMailer default_url_options in your environment config file? Either in config/environments/development.rb or config/environments/production.rb (depending on the environment you're working on), make sure you include the following:
config.action_mailer.default_url_options = { :host => "example.com" }
See more info here: http://api.rubyonrails.org/classes/ActionMailer/Base.html#label-Generating+URLs