diff --git a/lib/email/receiver.rb b/lib/email/receiver.rb
index be5ae2f2823..0a5ad7f7cb1 100644
--- a/lib/email/receiver.rb
+++ b/lib/email/receiver.rb
@@ -66,7 +66,7 @@ module Email
 
     def is_blacklisted?
       return false if SiteSetting.ignore_by_title.blank?
-      Regexp.new(SiteSetting.ignore_by_title) =~ @mail.subject
+      Regexp.new(SiteSetting.ignore_by_title, Regexp::IGNORECASE) =~ @mail.subject
     end
 
     def create_incoming_email
diff --git a/spec/components/email/receiver_spec.rb b/spec/components/email/receiver_spec.rb
index 51e655a6b28..6f6e7d50a31 100644
--- a/spec/components/email/receiver_spec.rb
+++ b/spec/components/email/receiver_spec.rb
@@ -568,11 +568,10 @@ describe Email::Receiver do
       expect { process(:tl4_user) }.to change(Topic, :count)
     end
 
-    it "ignores by title" do
+    it "ignores by case-insensitive title" do
       SiteSetting.ignore_by_title = "foo"
       expect { process(:ignored) }.to_not change(Topic, :count)
     end
-
   end
 
   context "new topic in a category that allows strangers" do
diff --git a/spec/components/validators/email_validator_spec.rb b/spec/components/validators/email_validator_spec.rb
index 71f6bb746ae..42ff521375d 100644
--- a/spec/components/validators/email_validator_spec.rb
+++ b/spec/components/validators/email_validator_spec.rb
@@ -21,11 +21,13 @@ describe EmailValidator do
     it "adds an error when email matches a blocked email" do
       ScreenedEmail.create!(email: 'sam@sam.com', action_type: ScreenedEmail.actions[:block])
       expect(blocks?('sam@sam.com')).to eq(true)
+      expect(blocks?('SAM@sam.com')).to eq(true)
     end
 
     it "blocks based on email_domains_blacklist" do
       SiteSetting.email_domains_blacklist = "email.com|mail.com|e-mail.com"
       expect(blocks?('sam@email.com')).to eq(true)
+      expect(blocks?('sam@EMAIL.com')).to eq(true)
       expect(blocks?('sam@bob.email.com')).to eq(true)
       expect(blocks?('sam@e-mail.com')).to eq(true)
       expect(blocks?('sam@googlemail.com')).to eq(false)
@@ -34,6 +36,7 @@ describe EmailValidator do
     it "blocks based on email_domains_whitelist" do
       SiteSetting.email_domains_whitelist = "googlemail.com|email.com"
       expect(blocks?('sam@email.com')).to eq(false)
+      expect(blocks?('sam@EMAIL.com')).to eq(false)
       expect(blocks?('sam@bob.email.com')).to eq(false)
       expect(blocks?('sam@e-mail.com')).to eq(true)
       expect(blocks?('sam@googlemail.com')).to eq(false)
diff --git a/spec/fixtures/emails/ignored.eml b/spec/fixtures/emails/ignored.eml
index 1eafc6a6d23..153a9efb410 100644
--- a/spec/fixtures/emails/ignored.eml
+++ b/spec/fixtures/emails/ignored.eml
@@ -1,7 +1,7 @@
 Return-Path: <foo@bar.com>
 From: Foo Bar <foo@bar.com>
 To: category@foo.com
-Subject: This is a foo topic
+Subject: This is a FoO topic
 Date: Fri, 15 Jan 2016 00:12:43 +0100
 Message-ID: <53@foo.bar.mail>
 Mime-Version: 1.0