diff --git a/lib/seek/config.rb b/lib/seek/config.rb
index 00110ab98d..b216834f0b 100644
--- a/lib/seek/config.rb
+++ b/lib/seek/config.rb
@@ -38,6 +38,8 @@ def smtp_propagate
       password =  smtp_settings 'password'
       smtp_hash['password'] = password
 
+      smtp_hash['enable_starttls_auto'] = false if smtp_hash['enable_starttls_auto'].nil?
+
       new_hash = {}
       smtp_hash.keys.each do |key|
         new_hash[key.to_sym] = smtp_hash[key]
diff --git a/test/unit/config_test.rb b/test/unit/config_test.rb
index 870064cf9b..d49311914e 100644
--- a/test/unit/config_test.rb
+++ b/test/unit/config_test.rb
@@ -358,6 +358,14 @@ class ConfigTest < ActiveSupport::TestCase
     refute setting[:encrypted_value].include?(password)
   end
 
+  test 'set enable_starttls_auto to false' do
+    Seek::Config.set_smtp_settings 'enable_starttls_auto', false
+
+    # must be false and not nil
+    refute_nil ActionMailer::Base.smtp_settings[:enable_starttls_auto]
+    refute ActionMailer::Base.smtp_settings[:enable_starttls_auto]
+  end
+
   test 'doi_prefix, doi_suffix' do
     assert_equal '10.5072', Seek::Config.doi_prefix
     assert_equal 'Sysmo.SEEK', Seek::Config.doi_suffix