generate recipient header with Mail::Address to properly handle non-ASCII characters

app/mailers/notification_mailers/base.rb

@@ -20,12 +20,18 @@ module NotificationMailers
       default_headers.merge(@headers)
     end
 
+    def name_and_address(name, email)
+      address = Mail::Address.new email
+      address.display_name = name
+      address.format
+    end
+
     private
     def default_headers
       headers = {
         :from => AppConfig[:smtp_sender_address],
         :host => "#{AppConfig[:pod_uri]}",
-        :to => "\"#{@recipient.name}\" <#{@recipient.email}>"
+        :to => name_and_address(@recipient.name, @recipient.email)
       }
 
       headers[:from] = "\"#{@sender.name} (Diaspora*)\" <#{AppConfig[:smtp_sender_address]}>" if @sender.present?
@@ -48,4 +54,4 @@ module NotificationMailers
       Rails.logger.info(log_string)
     end
   end
-end
\ No newline at end of file
+end

app/mailers/notification_mailers/confirm_email.rb

 module NotificationMailers
   class ConfirmEmail < NotificationMailers::Base
     def set_headers
-      @headers[:to] = "#{@recipient.profile.first_name} <#{@recipient.unconfirmed_email}>"
+      @headers[:to] = name_and_address(@recipient.profile.first_name, @recipient.unconfirmed_email)
       @headers[:subject] = I18n.t('notifier.confirm_email.subject', :unconfirmed_email => @recipient.unconfirmed_email)
     end
   end