diff --git a/ietf/ietfauth/tests.py b/ietf/ietfauth/tests.py
index 9fd75d06d..65334c682 100644
--- a/ietf/ietfauth/tests.py
+++ b/ietf/ietfauth/tests.py
@@ -381,6 +381,21 @@ class IetfAuthTests(TestCase):
         self.assertEqual(len(updated_roles), 1)
         self.assertEqual(updated_roles[0].email_id, new_email_address)
 
+    def test_email_case_insensitive_protection(self):
+        EmailFactory(address="TestAddress@example.net")
+        person = PersonFactory()
+        url = urlreverse(ietf.ietfauth.views.profile)
+        login_testing_unauthorized(self, person.user.username, url)
+
+        data = {
+            "name": person.name,
+            "plain": person.plain,
+            "ascii": person.ascii,
+            "active_emails": [e.address for e in person.email_set.filter(active=True)],
+            "new_email": "testaddress@example.net",
+        }
+        r = self.client.post(url, data)
+        self.assertContains(r, "Email address 'TestAddress@example.net' is already assigned", status_code=200)
 
     def test_nomcom_dressing_on_profile(self):
         url = urlreverse('ietf.ietfauth.views.profile')
diff --git a/ietf/person/migrations/0030_ci_email.py b/ietf/person/migrations/0030_ci_email.py
new file mode 100644
index 000000000..3a444988b
--- /dev/null
+++ b/ietf/person/migrations/0030_ci_email.py
@@ -0,0 +1,27 @@
+# Generated by Django 2.2.28 on 2023-01-26 19:45
+
+import django.contrib.postgres.fields.citext
+from django.contrib.postgres.operations import CITextExtension
+import django.core.validators
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('person', '0029_use_timezone_now_for_person_models'),
+    ]
+
+    operations = [
+        CITextExtension(),
+        migrations.AlterField(
+            model_name='email',
+            name='address',
+            field=django.contrib.postgres.fields.citext.CICharField(max_length=64, primary_key=True, serialize=False, validators=[django.core.validators.EmailValidator()]),
+        ),
+        migrations.AlterField(
+            model_name='historicalemail',
+            name='address',
+            field=django.contrib.postgres.fields.citext.CICharField(db_index=True, max_length=64, validators=[django.core.validators.EmailValidator()]),
+        ),
+    ]
diff --git a/ietf/person/models.py b/ietf/person/models.py
index a7e30b2de..02cee4d67 100644
--- a/ietf/person/models.py
+++ b/ietf/person/models.py
@@ -12,6 +12,7 @@ from urllib.parse import urljoin
 
 from django.conf import settings
 from django.contrib.auth.models import User
+from django.contrib.postgres.fields import CICharField
 from django.core.exceptions import ValidationError
 from django.core.validators import validate_email
 from django.db import models
@@ -277,7 +278,7 @@ class Alias(models.Model):
 
 class Email(models.Model):
     history = HistoricalRecords()
-    address = models.CharField(max_length=64, primary_key=True, validators=[validate_email])
+    address = CICharField(max_length=64, primary_key=True, validators=[validate_email])
     person = ForeignKey(Person, null=True)
     time = models.DateTimeField(auto_now_add=True)
     primary = models.BooleanField(default=False)
diff --git a/ietf/settings_postgrestest.py b/ietf/settings_postgrestest.py
index e6f53f09a..450fd9180 100755
--- a/ietf/settings_postgrestest.py
+++ b/ietf/settings_postgrestest.py
@@ -37,7 +37,7 @@ MIGRATION_MODULES = DisableMigrations()
 DATABASES = {
     'default': {
         'HOST': 'db',
-        'PORT': 5432,
+        'PORT': '5432',
         'NAME': 'test.db',
         'ENGINE': 'django.db.backends.postgresql_psycopg2',
         'USER': 'django',