diff --git a/Gemfile b/Gemfile
index 13d51f292..f2c01a6fa 100644
--- a/Gemfile
+++ b/Gemfile
@@ -18,7 +18,7 @@ gem "actionpack-xml_parser"
 gem "roadie-rails", "~> 1.1.1"
 gem "roadie", "~> 3.2.1"
 gem "mimemagic"
-gem "mail", "~> 2.6.6"
+gem "mail", "~> 2.6.4"
 
 gem "nokogiri", (RUBY_VERSION >= "2.1" ? "~> 1.8.1" : "~> 1.6.8")
 gem "i18n", "~> 0.7.0"