diff --git a/actionmailer/lib/action_mailer/base.rb b/actionmailer/lib/action_mailer/base.rb
index 34f54db720..94d4c59d3a 100644
--- a/actionmailer/lib/action_mailer/base.rb
+++ b/actionmailer/lib/action_mailer/base.rb
@@ -14,7 +14,7 @@ module ActionMailer
#
# Action Mailer allows you to send email from your application using a mailer model and views.
#
- # = Mailer Models
+ # == Mailer Models
#
# To use Action Mailer, you need to create a mailer model.
#
@@ -86,7 +86,7 @@ module ActionMailer
# format.html { render "some_other_template" }
# end
#
- # = Mailer views
+ # == Mailer views
#
# Like Action Controller, each mailer class has a corresponding view directory in which each
# method of the class looks for a template with its name.
@@ -114,7 +114,7 @@ module ActionMailer
# <%= truncate(@note.body, length: 25) %>
#
#
- # = Generating URLs
+ # == Generating URLs
#
# URLs can be generated in mailer views using url_for or named routes. Unlike controllers from
# Action Pack, the mailer instance doesn't have any context about the incoming request, so you'll need
@@ -142,7 +142,7 @@ module ActionMailer
#
# By default when config.force_ssl is +true+, URLs generated for hosts will use the HTTPS protocol.
#
- # = Sending mail
+ # == Sending mail
#
# Once a mailer action and template are defined, you can deliver your message or defer its creation and
# delivery for later:
@@ -167,7 +167,7 @@ module ActionMailer
# You never instantiate your mailer class. Rather, you just call the method you defined on the class itself.
# All instance methods are expected to return a message object to be sent.
#
- # = Multipart Emails
+ # == Multipart Emails
#
# Multipart messages can also be used implicitly because Action Mailer will automatically detect and use
# multipart templates, where each template is named after the name of the action, followed by the content
@@ -188,7 +188,7 @@ module ActionMailer
# This means that you'll have to manually add each part to the email and set the content type of the email
# to multipart/alternative.
#
- # = Attachments
+ # == Attachments
#
# Sending attachment in emails is easy:
#
@@ -228,7 +228,7 @@ module ActionMailer
# end
# end
#
- # = Inline Attachments
+ # == Inline Attachments
#
# You can also specify that a file should be displayed inline with other HTML. This is useful
# if you want to display a corporate logo or a photo.
@@ -254,7 +254,7 @@ module ActionMailer
#
# <%= image_tag attachments['photo.png'].url, alt: 'Our Photo', class: 'photo' -%>
#
- # = Observing and Intercepting Mails
+ # == Observing and Intercepting Mails
#
# Action Mailer provides hooks into the Mail observer and interceptor methods. These allow you to
# register classes that are called during the mail delivery life cycle.
@@ -267,7 +267,7 @@ module ActionMailer
# the delivery agents. Your class should make any needed modifications directly to the passed
# in +Mail::Message+ instance.
#
- # = Default \Hash
+ # == Default \Hash
#
# Action Mailer provides some intelligent defaults for your emails, these are usually specified in a
# default method inside the class definition:
@@ -316,7 +316,7 @@ module ActionMailer
#
# config.action_mailer.default_options = { from: "no-reply@example.org" }
#
- # = \Callbacks
+ # == \Callbacks
#
# You can specify callbacks using before_action and after_action for configuring your messages,
# and using before_deliver and after_deliver for wrapping the delivery process.
@@ -350,7 +350,7 @@ module ActionMailer
# using before_action rather than after_action in your
# Action Mailer classes so that headers are parsed properly.
#
- # = Rescuing Errors
+ # == Rescuing Errors
#
# +rescue+ blocks inside of a mailer method cannot rescue errors that occur
# outside of rendering -- for example, record deserialization errors in a
@@ -373,7 +373,7 @@ module ActionMailer
# end
# end
#
- # = Previewing emails
+ # == Previewing emails
#
# You can preview your email templates visually by adding a mailer preview file to the
# ActionMailer::Base.preview_paths. Since most emails do something interesting
@@ -410,7 +410,7 @@ module ActionMailer
# and register_preview_interceptor if they should operate on both sending and
# previewing emails.
#
- # = Configuration options
+ # == Configuration options
#
# These options are specified on the class level, like
# ActionMailer::Base.raise_delivery_errors = true