diff --git a/app/dashboard/templates/dashboard/domain_detail/info.html b/app/dashboard/templates/dashboard/domain_detail/info.html
index 6274e85f..f279e91e 100644
--- a/app/dashboard/templates/dashboard/domain_detail/info.html
+++ b/app/dashboard/templates/dashboard/domain_detail/info.html
@@ -57,7 +57,7 @@
   </div>
 
   <hr>
-  <div>Default Alias name</div>
+  <div>Default Alias Name</div>
   <div class="small-text">
     This name will be used as the default alias name when you send
     or reply from an alias, unless overwritten by the alias specific name.
@@ -76,6 +76,32 @@
     </form>
   </div>
 
+  <hr>
+  <div>Random Prefix Generation</div>
+  <div class="small-text">
+    A random prefix can be generated for this domain for usage in the New Alias
+    feature.
+  </div>
+
+  <div>
+    <form method="post">
+      <input type="hidden" name="form-name" value="switch-random-prefix-generation">
+      <label class="custom-switch cursor mt-2 pl-0"
+             data-toggle="tooltip"
+          {% if custom_domain.random_prefix_generation %}
+             title="Disable random prefix generation"
+          {% else %}
+             title="Enable random prefix generation"
+          {% endif %}
+      >
+        <input type="checkbox" class="custom-switch-input"
+            {{ "checked" if custom_domain.random_prefix_generation else "" }}>
+
+        <span class="custom-switch-indicator"></span>
+      </label>
+    </form>
+  </div>
+
   <hr>
   <h3 class="mb-0">Delete Domain</h3>
   <div class="small-text mb-3">Please note that this operation is irreversible.
@@ -119,4 +145,4 @@
       })
     });
   </script>
-{% endblock %}
\ No newline at end of file
+{% endblock %}
diff --git a/app/dashboard/views/custom_alias.py b/app/dashboard/views/custom_alias.py
index 55ad0f6a..ad89c0f4 100644
--- a/app/dashboard/views/custom_alias.py
+++ b/app/dashboard/views/custom_alias.py
@@ -8,7 +8,6 @@ from app.config import (
     CUSTOM_ALIAS_SECRET,
 )
 from app.dashboard.base import dashboard_bp
-from app.email_utils import email_belongs_to_alias_domains
 from app.extensions import db
 from app.log import LOG
 from app.models import (
@@ -27,15 +26,19 @@ signer = TimestampSigner(CUSTOM_ALIAS_SECRET)
 
 def available_suffixes(user: User) -> [bool, str, str]:
     """Return (is_custom_domain, alias-suffix, time-signed alias-suffix)"""
-    user_custom_domains = [cd.domain for cd in user.verified_custom_domains()]
+    user_custom_domains = user.verified_custom_domains()
 
     # List of (is_custom_domain, alias-suffix, time-signed alias-suffix)
     suffixes = []
 
     # put custom domain first
+    # for each user domain, generate both the domain and a random suffix version
     for alias_domain in user_custom_domains:
-        suffix = "@" + alias_domain
+        suffix = "@" + alias_domain.domain
         suffixes.append((True, suffix, signer.sign(suffix).decode()))
+        if alias_domain.random_prefix_generation:
+            suffix = "." + random_word() + "@" + alias_domain.domain
+            suffixes.append((True, suffix, signer.sign(suffix).decode()))
 
     # then default domain
     for domain in ALIAS_DOMAINS:
@@ -193,35 +196,23 @@ def verify_prefix_suffix(user, alias_prefix, alias_suffix) -> bool:
 
     # make sure alias_suffix is either .random_word@simplelogin.co or @my-domain.com
     alias_suffix = alias_suffix.strip()
-    if alias_suffix.startswith("@"):
-        alias_domain = alias_suffix[1:]
-        # alias_domain can be either custom_domain or if DISABLE_ALIAS_SUFFIX, one of the default ALIAS_DOMAINS
-        if DISABLE_ALIAS_SUFFIX:
-            if (
-                alias_domain not in user_custom_domains
-                and alias_domain not in ALIAS_DOMAINS
-            ):
-                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
-                return False
-        else:
-            if alias_domain not in user_custom_domains:
-                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
-                return False
-    else:
-        if not alias_suffix.startswith("."):
+    # alias_domain_prefix is either a .random_word or ""
+    alias_domain_prefix, alias_domain = alias_suffix.split("@", 1)
+
+    # alias_domain must be either one of user custom domains or built-in domains
+    if alias_domain not in user_custom_domains and alias_domain not in ALIAS_DOMAINS:
+        LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
+        return False
+
+    # built-in domain case:
+    # 1) alias_suffix must start with "." and
+    # 2) alias_domain_prefix must come from the word list
+    if alias_domain in ALIAS_DOMAINS and alias_domain not in user_custom_domains:
+        if not alias_domain_prefix.startswith("."):
             LOG.exception("User %s submits a wrong alias suffix %s", user, alias_suffix)
             return False
 
-        full_alias = alias_prefix + alias_suffix
-        if not email_belongs_to_alias_domains(full_alias):
-            LOG.exception(
-                "Alias suffix should end with one of the alias domains %s",
-                user,
-                alias_suffix,
-            )
-            return False
-
-        random_word_part = alias_suffix[1 : alias_suffix.find("@")]
+        random_word_part = alias_domain_prefix[1:]
         if not word_exist(random_word_part):
             LOG.exception(
                 "alias suffix %s needs to start with a random word, user %s",
@@ -229,5 +220,14 @@ def verify_prefix_suffix(user, alias_prefix, alias_suffix) -> bool:
                 user,
             )
             return False
+    else:
+        if alias_domain not in user_custom_domains:
+            if not DISABLE_ALIAS_SUFFIX:
+                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
+                return False
+
+            if alias_domain not in ALIAS_DOMAINS:
+                LOG.exception("wrong alias suffix %s, user %s", alias_suffix, user)
+                return False
 
     return True
diff --git a/app/dashboard/views/domain_detail.py b/app/dashboard/views/domain_detail.py
index 4d539175..09f5c604 100644
--- a/app/dashboard/views/domain_detail.py
+++ b/app/dashboard/views/domain_detail.py
@@ -160,6 +160,25 @@ def domain_detail(custom_domain_id):
             return redirect(
                 url_for("dashboard.domain_detail", custom_domain_id=custom_domain.id)
             )
+        elif request.form.get("form-name") == "switch-random-prefix-generation":
+            custom_domain.random_prefix_generation = (
+                not custom_domain.random_prefix_generation
+            )
+            db.session.commit()
+
+            if custom_domain.random_prefix_generation:
+                flash(
+                    f"Random prefix generation has been enabled for {custom_domain.domain}",
+                    "success",
+                )
+            else:
+                flash(
+                    f"Random prefix generation has been disabled for {custom_domain.domain}",
+                    "warning",
+                )
+            return redirect(
+                url_for("dashboard.domain_detail", custom_domain_id=custom_domain.id)
+            )
         elif request.form.get("form-name") == "delete":
             name = custom_domain.domain
             CustomDomain.delete(custom_domain_id)
diff --git a/app/models.py b/app/models.py
index e34b89a6..9b558a9a 100644
--- a/app/models.py
+++ b/app/models.py
@@ -1449,6 +1449,11 @@ class CustomDomain(db.Model, ModelMixin):
     # an alias is created automatically the first time it receives an email
     catch_all = db.Column(db.Boolean, nullable=False, default=False, server_default="0")
 
+    # option to generate random prefix version automatically
+    random_prefix_generation = db.Column(
+        db.Boolean, nullable=False, default=False, server_default="0"
+    )
+
     user = db.relationship(User, foreign_keys=[user_id])
 
     @property
diff --git a/migrations/versions/2020_100922_a90e423c6763_.py b/migrations/versions/2020_100922_a90e423c6763_.py
new file mode 100644
index 00000000..1014020c
--- /dev/null
+++ b/migrations/versions/2020_100922_a90e423c6763_.py
@@ -0,0 +1,29 @@
+"""empty message
+
+Revision ID: a90e423c6763
+Revises: 1abfc9e14d7e
+Create Date: 2020-10-09 22:35:11.359186
+
+"""
+import sqlalchemy_utils
+from alembic import op
+import sqlalchemy as sa
+
+
+# revision identifiers, used by Alembic.
+revision = 'a90e423c6763'
+down_revision = '1abfc9e14d7e'
+branch_labels = None
+depends_on = None
+
+
+def upgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.add_column('custom_domain', sa.Column('random_prefix_generation', sa.Boolean(), server_default='0', nullable=False))
+    # ### end Alembic commands ###
+
+
+def downgrade():
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_column('custom_domain', 'random_prefix_generation')
+    # ### end Alembic commands ###