diff --git a/app/api/serializer.py b/app/api/serializer.py
index 2d9546b6..21b801de 100644
--- a/app/api/serializer.py
+++ b/app/api/serializer.py
@@ -204,7 +204,7 @@ def get_alias_infos_with_pagination_v3(
     q = list(q.limit(page_limit).offset(page_id * page_size))
 
     ret = []
-    for alias, contact, email_log, custom_domain, nb_reply, nb_blocked, nb_forward in q:
+    for alias, contact, email_log, nb_reply, nb_blocked, nb_forward in q:
         ret.append(
             AliasInfo(
                 alias=alias,
@@ -215,7 +215,7 @@ def get_alias_infos_with_pagination_v3(
                 nb_reply=nb_reply,
                 latest_email_log=email_log,
                 latest_contact=contact,
-                custom_domain=custom_domain,
+                custom_domain=alias.custom_domain,
             )
         )
 
@@ -318,7 +318,7 @@ def get_alias_info_v3(user: User, alias_id: int) -> AliasInfo:
     q = construct_alias_query(user)
     q = q.filter(Alias.id == alias_id)
 
-    for alias, contact, email_log, custom_domain, nb_reply, nb_blocked, nb_forward in q:
+    for alias, contact, email_log, nb_reply, nb_blocked, nb_forward in q:
         return AliasInfo(
             alias=alias,
             mailbox=alias.mailbox,
@@ -328,7 +328,7 @@ def get_alias_info_v3(user: User, alias_id: int) -> AliasInfo:
             nb_reply=nb_reply,
             latest_email_log=email_log,
             latest_contact=contact,
-            custom_domain=custom_domain,
+            custom_domain=alias.custom_domain,
         )
 
 
@@ -379,14 +379,13 @@ def construct_alias_query(user: User):
             Alias,
             Contact,
             EmailLog,
-            CustomDomain,
             alias_activity_subquery.c.nb_reply,
             alias_activity_subquery.c.nb_blocked,
             alias_activity_subquery.c.nb_forward,
         )
         .options(joinedload(Alias.hibp_breaches))
+        .options(joinedload(Alias.custom_domain))
         .join(Contact, Alias.id == Contact.alias_id, isouter=True)
-        .join(CustomDomain, Alias.custom_domain_id == CustomDomain.id, isouter=True)
         .join(EmailLog, Contact.id == EmailLog.contact_id, isouter=True)
         .filter(Alias.id == alias_activity_subquery.c.id)
         .filter(Alias.id == alias_contact_subquery.c.id)
diff --git a/app/models.py b/app/models.py
index 512a3050..4c05683d 100644
--- a/app/models.py
+++ b/app/models.py
@@ -1160,7 +1160,7 @@ class Alias(Base, ModelMixin):
     enabled = sa.Column(sa.Boolean(), default=True, nullable=False)
 
     custom_domain_id = sa.Column(
-        sa.ForeignKey("custom_domain.id", ondelete="cascade"), nullable=True
+        sa.ForeignKey("custom_domain.id", ondelete="cascade"), nullable=True, index=True
     )
 
     custom_domain = orm.relationship("CustomDomain", foreign_keys=[custom_domain_id])
@@ -1172,7 +1172,7 @@ class Alias(Base, ModelMixin):
 
     # to know whether an alias belongs to a directory
     directory_id = sa.Column(
-        sa.ForeignKey("directory.id", ondelete="cascade"), nullable=True
+        sa.ForeignKey("directory.id", ondelete="cascade"), nullable=True, index=True
     )
 
     note = sa.Column(sa.Text, default=None, nullable=True)
diff --git a/migrations/versions/2022_022617_5047fcbd57c7_.py b/migrations/versions/2022_022617_5047fcbd57c7_.py
new file mode 100644
index 00000000..0485d29d
--- /dev/null
+++ b/migrations/versions/2022_022617_5047fcbd57c7_.py
@@ -0,0 +1,31 @@
+"""empty message
+
+Revision ID: 5047fcbd57c7
+Revises: 9282e982bc05
+Create Date: 2022-02-26 17:51:03.379676
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '5047fcbd57c7'
+down_revision = '9282e982bc05'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_index(op.f('ix_alias_custom_domain_id'), 'alias', ['custom_domain_id'], unique=False)
+    op.create_index(op.f('ix_alias_directory_id'), 'alias', ['directory_id'], unique=False)
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_index(op.f('ix_alias_directory_id'), table_name='alias')
+    op.drop_index(op.f('ix_alias_custom_domain_id'), table_name='alias')
+    # ### end Alembic commands ###
diff --git a/templates/dashboard/index.html b/templates/dashboard/index.html
index 853206fb..225c3cf0 100644
--- a/templates/dashboard/index.html
+++ b/templates/dashboard/index.html
@@ -284,7 +284,7 @@
                 </a>
               {% endif %}
 
-              {% if alias_info.custom_domain and not alias_info.custom_domain.verified %}
+              {% if alias.custom_domain and not alias.custom_domain.verified %}
                 <span class="fa fa-warning text-warning" data-toggle="tooltip"
                       title="Alias can't receive emails as its domain doesn't have MX records set up."></span>
               {% endif %}