diff --git a/app/dashboard/views/setting.py b/app/dashboard/views/setting.py
index 576cdeef..50699628 100644
--- a/app/dashboard/views/setting.py
+++ b/app/dashboard/views/setting.py
@@ -28,6 +28,7 @@ from app.email_utils import (
 )
 from app.log import LOG
 from app.models import (
+    BlockBehaviourEnum,
     PlanEnum,
     File,
     ResetPasswordCode,
@@ -303,7 +304,17 @@ def setting():
             Session.commit()
             flash("Your preference has been updated", "success")
             return redirect(url_for("dashboard.setting"))
-
+        elif request.form.get("form-name") == "change-blocked-behaviour":
+            choose = request.form.get("blocked-behaviour")
+            if choose == str(BlockBehaviourEnum.return_2xx.value):
+                current_user.block_behaviour = BlockBehaviourEnum.return_2xx.name
+            elif choose == str(BlockBehaviourEnum.return_5xx.value):
+                current_user.block_behaviour = BlockBehaviourEnum.return_5xx.name
+            else:
+                flash("There was an error. Please try again", "warning")
+                return redirect(url_for("dashboard.setting"))
+            Session.commit()
+            flash("Your preference has been updated", "success")
         elif request.form.get("form-name") == "export-data":
             return redirect(url_for("api.export_data"))
         elif request.form.get("form-name") == "export-alias":
@@ -318,6 +329,7 @@ def setting():
         form=form,
         PlanEnum=PlanEnum,
         SenderFormatEnum=SenderFormatEnum,
+        BlockBehaviourEnum=BlockBehaviourEnum,
         promo_form=promo_form,
         change_email_form=change_email_form,
         pending_email=pending_email,
diff --git a/app/models.py b/app/models.py
index 40bc0227..512a3050 100644
--- a/app/models.py
+++ b/app/models.py
@@ -221,6 +221,11 @@ class AliasSuffixEnum(EnumE):
     random_string = 1  # Completely random string
 
 
+class BlockBehaviourEnum(EnumE):
+    return_2xx = 0
+    return_5xx = 1
+
+
 class Hibp(Base, ModelMixin):
     __tablename__ = "hibp"
     name = sa.Column(sa.String(), nullable=False, unique=True, index=True)
@@ -438,6 +443,13 @@ class User(Base, ModelMixin, UserMixin, PasswordOracle):
     # in minutes
     phone_quota = sa.Column(sa.Integer, nullable=True)
 
+    # Status code to return if is blocked
+    block_behaviour = sa.Column(
+        sa.Enum(BlockBehaviourEnum),
+        nullable=False,
+        server_default=BlockBehaviourEnum.return_2xx.name,
+    )
+
     @property
     def directory_quota(self):
         return min(
diff --git a/email_handler.py b/email_handler.py
index 61f503f3..da4049ef 100644
--- a/email_handler.py
+++ b/email_handler.py
@@ -139,6 +139,7 @@ from app.log import LOG, set_message_id
 from app.models import (
     Alias,
     Contact,
+    BlockBehaviourEnum,
     EmailLog,
     User,
     RefusedEmail,
@@ -606,8 +607,13 @@ def handle_forward(envelope, msg: Message, rcpt_to: str) -> List[Tuple[bool, str
             alias_id=contact.alias_id,
             commit=True,
         )
+
+        res_status = status.E200
+        if user.block_behaviour == BlockBehaviourEnum.return_5xx:
+            res_status = status.E502
+
         # do not return 5** to allow user to receive emails later when alias is enabled or contact is unblocked
-        return [(True, status.E200)]
+        return [(True, res_status)]
 
     ret = []
     mailboxes = alias.mailboxes
diff --git a/migrations/versions/2022_021812_9282e982bc05_.py b/migrations/versions/2022_021812_9282e982bc05_.py
new file mode 100644
index 00000000..6a0d021e
--- /dev/null
+++ b/migrations/versions/2022_021812_9282e982bc05_.py
@@ -0,0 +1,38 @@
+"""Add block_behaviour setting for user
+
+Revision ID: 9282e982bc05
+Revises: 07b870d7cc86
+Create Date: 2022-02-18 12:37:55.707424
+
+"""
+import sqlalchemy_utils
+from sqlalchemy.dialects import postgresql
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = '9282e982bc05'
+down_revision = '07b870d7cc86'
+branch_labels = None
+depends_on = None
+
+def __create_enum() -> postgresql.ENUM:
+    return postgresql.ENUM('return_2xx', 'return_5xx', name='block_behaviour_enum')
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    block_behaviour_enum = __create_enum()
+    block_behaviour_enum.create(op.get_bind())
+
+    op.add_column('users', sa.Column('block_behaviour', block_behaviour_enum, nullable=False, default='return_2xx', server_default='return_2xx'))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('users', 'block_behaviour')
+
+    block_behaviour_enum = __create_enum()
+    block_behaviour_enum.drop(op.get_bind())
+    # ### end Alembic commands ###
diff --git a/templates/dashboard/setting.html b/templates/dashboard/setting.html
index 62008165..7148173b 100644
--- a/templates/dashboard/setting.html
+++ b/templates/dashboard/setting.html
@@ -490,6 +490,34 @@
       </div>
     </div>
 
+    <div class="card" id="blocked-behaviour">
+      <div class="card-body">
+        <div class="card-title">Blocked contact behaviour</div>
+        <div class="mb-3">
+          When an email is sent to one of your blocked contacts you can decide what response they should see. <br>
+          If you select "Ignore", they will see the message as delivered, but we won't actually forward it to you. <br>
+          If you select "Reject", we will tell them that the alias they have does not exist.
+        </div>
+        <form method="post" action="#blocked-behaviour" class="form-inline">
+          <input type="hidden" name="form-name" value="change-blocked-behaviour">
+
+          <select class="form-control mr-sm-2" name="blocked-behaviour">
+              <option value="{{ BlockBehaviourEnum.return_2xx.value }}"
+                      {% if current_user.block_behaviour.value == BlockBehaviourEnum.return_2xx.value %} selected="selected" {% endif %}>
+                  Ignore (the sender will see the email as delivered, but you won't receive anything).
+              </option>
+              <option value="{{ BlockBehaviourEnum.return_5xx.value }}"
+                      {% if current_user.block_behaviour.value == BlockBehaviourEnum.return_5xx.value %} selected="selected" {% endif %}>
+                  Reject (the sender will be told that your alias does not exist).
+              </option>
+
+          </select>
+
+          <button class="btn btn-outline-primary">Update</button>
+        </form>
+      </div>
+    </div>
+
     <div class="card">
       <div class="card-body">
         <div class="card-title">Alias Import</div>