Support sendgrid ip pool feature in X-SMTPAPI Header

README.rdoc

@@ -71,6 +71,20 @@ Mailer class definition:
           end
         end
 
+=== Setting ip pool
+
+    Mailer class definition:
+
+        class Mailer < ActionMailer::Base
+          default :from => '[email protected]',
+                  :subject => 'An email sent via SendGridSmtpApi with substitutions'
+
+          def email_with_ip_pool
+            ip_pool 'IPPoolName'
+            mail :to => '[email protected]'
+          end
+        end
+
 == Apps (formerly called Filters)
 
 Apps can be applied to any of your email messages and can be configured through SendGridSmtpApi gem.

lib/send_grid.rb

@@ -6,7 +6,7 @@ module SendGridSmtpApi
   def self.included(base)
     base.class_eval do
       prepend InstanceMethods
-      delegate :substitute, :uniq_args, :category, :add_filter_setting, :standard_smtp, :to => :sendgrid_header
+      delegate :substitute, :uniq_args, :category, :add_filter_setting, :ip_pool, :standard_smtp, :to => :sendgrid_header
       alias_method :sendgrid_header, :send_grid_header
     end
   end

lib/send_grid/api_header.rb

@@ -26,12 +26,15 @@ def add_filter_setting(fltr, setting, val)
     @data[:filters][fltr][:settings][setting] = val
   end
 
+  def ip_pool(pool_name)
+    @data[:ip_pool] = pool_name
+  end
+
   def to_json
     JSON.generate(@data, {:indent => " ", :space => "", :space_before => "", :object_nl => "", :array_nl => ""})
   end
 
   def standard_smtp(enabled = false)
     @standard_smtp = enabled
   end
-
 end

spec/api_header_spec.rb

@@ -36,5 +36,10 @@
       header.add_filter_setting :filter1, :setting1, 'val1'
       header.to_json.should eql '{ "filters":{  "filter1":{   "settings":{    "setting1":"val1"   }  } }}'
     end
+
+    it "contains ip_pool" do
+      header.ip_pool 'pool_name'
+      header.to_json.should eql '{ "ip_pool":"pool_name"}'
+    end
   end
 end