diff --git a/sensu-plugins-mailer.gemspec b/sensu-plugins-mailer.gemspec
index 564aee4..d954b01 100644
--- a/sensu-plugins-mailer.gemspec
+++ b/sensu-plugins-mailer.gemspec
@@ -28,7 +28,7 @@ Gem::Specification.new do |s|
   s.version                = SensuPluginsMailer::Version::VER_STRING
 
   s.add_runtime_dependency 'aws-ses',           '0.6.0'
-  s.add_runtime_dependency 'mail',              '2.6.3'
+  s.add_runtime_dependency 'mail',              '2.7.1'
   s.add_runtime_dependency 'mailgun-ruby',      '1.0.3'
   s.add_runtime_dependency 'sensu-plugin',      '~> 4.0'
   s.add_runtime_dependency 'erubis',            '2.7.0'