SES domains are case-insensitive (#4050)

moto/ses/models.py

@@ -137,7 +137,8 @@ class SESBackend(BaseBackend):
         self.email_addresses.append(address)
 
     def verify_domain(self, domain):
-        self.domains.append(domain)
+        if domain.lower() not in self.domains:
+            self.domains.append(domain.lower())
 
     def list_identities(self):
         return self.domains + self.addresses

tests/test_ses/test_ses_boto3.py

@@ -8,7 +8,7 @@ from six.moves.email_mime_text import MIMEText
 import pytest
 
 
-# import sure  # noqa
+import sure  # noqa
 
 from moto import mock_ses
 
@@ -598,3 +598,19 @@ def test_update_ses_template():
     result["Template"]["HtmlPart"].should.equal(
         "<h1>Hello {{name}},</h1><p>Your favorite color is {{color}}</p>"
     )
+
+
+@mock_ses
+def test_domains_are_case_insensitive():
+    client = boto3.client("ses", region_name="us-east-1")
+    duplicate_domains = [
+        "EXAMPLE.COM",
+        "EXAMple.Com",
+        "example.com",
+    ]
+    for domain in duplicate_domains:
+        client.verify_domain_identity(Domain=domain)
+        client.verify_domain_dkim(Domain=domain)
+        identities = client.list_identities(IdentityType="Domain")["Identities"]
+        identities.should.have.length_of(1)
+        identities[0].should.equal("example.com")