diff --git a/openedx/features/sdaia_features/course_progress/migrations/0002_coursecompletionemailhistory_is_completion_email_sent.py b/openedx/features/sdaia_features/course_progress/migrations/0002_coursecompletionemailhistory_is_completion_email_sent.py
new file mode 100644
index 000000000000..f23fb28688bb
--- /dev/null
+++ b/openedx/features/sdaia_features/course_progress/migrations/0002_coursecompletionemailhistory_is_completion_email_sent.py
@@ -0,0 +1,18 @@
+# Generated by Django 3.2.20 on 2024-03-05 12:46
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('course_progress', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='coursecompletionemailhistory',
+            name='is_completion_email_sent',
+            field=models.BooleanField(default=False),
+        ),
+    ]
diff --git a/openedx/features/sdaia_features/course_progress/models.py b/openedx/features/sdaia_features/course_progress/models.py
index 7dfbb84d9d6b..0180d28ad69b 100644
--- a/openedx/features/sdaia_features/course_progress/models.py
+++ b/openedx/features/sdaia_features/course_progress/models.py
@@ -14,3 +14,4 @@ class CourseCompletionEmailHistory(models.Model):
     user = models.ForeignKey(User, on_delete=models.CASCADE)
     course_key = CourseKeyField(max_length=255, db_index=True)
     last_progress_email_sent = models.IntegerField(default=0)
+    is_completion_email_sent = models.BooleanField(default=False)
diff --git a/openedx/features/sdaia_features/course_progress/tasks.py b/openedx/features/sdaia_features/course_progress/tasks.py
index 08a9645f0c6e..766096f70785 100644
--- a/openedx/features/sdaia_features/course_progress/tasks.py
+++ b/openedx/features/sdaia_features/course_progress/tasks.py
@@ -60,9 +60,9 @@ def send_user_course_progress_email(current_progress, progress_last_email_sent_a
     site_domain = configuration_helpers.get_value_for_org(
         course.org,
         'site_domain',
-        settings.LMS_HOST
+        settings.LMS_BASE
     )
-    site = Site.objects.get(domain=site_domain)
+    site = Site.objects.filter(domain=site_domain).first() or Site.objects.first() or Site.objects.get_current()
     message_context = get_base_template_context(site)
     course_home_url = get_learning_mfe_home_url(course_key=course_key, url_fragment='home')
     platform_name = configuration_helpers.get_value_for_org(
@@ -104,6 +104,9 @@ def send_user_course_progress_email(current_progress, progress_last_email_sent_a
 def send_user_course_completion_email(user_id, course_key):
     course_id = CourseKey.from_string(course_key)
     user = User.objects.get(id=user_id)
+    user_completion_progress_email_history, _ = CourseCompletionEmailHistory.objects.get_or_create(user=user, course_key=course_key)
+    if user_completion_progress_email_history.is_completion_email_sent:
+        return
     collected_block_structure = get_block_structure_manager(course_id).get_collected()
     course_grade = CourseGradeFactory().read(user, collected_block_structure=collected_block_structure)
     passing_grade = int(course_grade.percent * 100)
@@ -112,9 +115,9 @@ def send_user_course_completion_email(user_id, course_key):
     site_domain = configuration_helpers.get_value_for_org(
         course.org,
         'site_domain',
-        settings.LMS_HOST
+        settings.LMS_BASE
     )
-    site = Site.objects.get(domain=site_domain)
+    site = Site.objects.filter(domain=site_domain).first() or Site.objects.first() or Site.objects.get_current()
     message_context = get_base_template_context(site)
     course_progress_url = get_learning_mfe_home_url(course_key=course_key, url_fragment='progress')
     platform_name = configuration_helpers.get_value_for_org(
@@ -140,6 +143,8 @@ def send_user_course_completion_email(user_id, course_key):
                 user_context={'full_name': user.profile.name}
             )
             ace.send(msg)
+            user_completion_progress_email_history.is_completion_email_sent = True
+            user_completion_progress_email_history.save()
             logger.info('course completion email sent to user:')
             return True
     except Exception as e:  # pylint: disable=broad-except